Yes, why is the Bishop of Rome the leader of Jesus' Church on earth--or Pope? There are two distinct issues here. One is about Petrine leadership, and the second issue is why the Bishop of Rome is Peter's successor.

I have four questions. 

1. Did Jesus make Peter leader of his disciples and Church?
2. Does the Church need this Petrine leadership?
3. Is Petrine leadership transferable?
4. Why is Rome the instantiation of Petrine leadership?

Did Jesus make Peter leader of his disciples and Church?
This is an easy one. Yes!  John 21:15-19 is the clearest expression of this. Peter loved Jesus more than any of the other disciples, and Jesus told him to tend his lambs, feed his sheep, and feed his sheep. This is unambiguous. 

Does the Church need Petrine Leadership?
Yes!
Mt 16:18 tells us that Jesus declared to Cephas, "You are Peter" and "upon this rock I will build my church . . ." This follows Peter confessing that Jesus is the Messiah and the Son of God. And Jesus says that God revealed that to Peter. It was not a deduction, but it was a gift of faith that no one else possessed (except, of course, Mary and maybe his family). The "this" of Mat 16:19 may be Peter or it may be Peter's declaration, but it doesn't matter. Because the Church is built on the testimony of the Apostles and not abstract claims. So, even if one argues that the "this rock" does not refer to Peter, it refers to Peter's confession (not some abstract claim). His confession that Jesus is Messiah and the Son of God was revealed to him, and it is his faith that becomes foundational for what is to follow. The Christian faith is not based on the fact that Jesus Christ is the Son of God and Messiah, but that Peter and the other apostles say that Jesus is the Son of God and Messiah. The faith is 100% based on the testimony of the Apostles, especially Peter.


So the question is not whether Peter's leadership is necessary. That's irrelevant. The issue is that Jesus declared it to be so. 

Is Petrine Leadership Transferable?
Now this is where it gets tricky and strange. I don't believe that the faith demands it. However, two things are relevant here. One is that both Matthew and John indicate that Peter's leadership is ongoing. In John, as long as there are lambs and sheep, then Peter's leadership is what Jesus desires. In Matthew, as long as there is a church being built, then the rock is needed. So it would stand to reason that as long as there's a church, Petrine leadership is needed and, unless Peter were to live forever, someone else would need to continue that leadership. The other piece of this discussion, which is underrated, is that the Church has the power to institute the transferability of Petrine leadership. Mt 16:19 says, "I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven." The Church has the authority to continue Peter's leadership, whether it is explicitly declared or not. The issue is did the Church do so? The answer has to be yes, since we have had Petrine leadership for centuries now. So my take is that Jesus didn't authorize any transferability of Petrine leadership, but the Church can and did.

Why is the Bishop of Rome the Successor of Peter?
 . . .
The arguments are that Peter was Bishop of Rome (such as it is) and that both Peter and Paul were martyred in Rome, making Rome special. The latter argument is ridiculous. I'll up you one. Jesus died in Jerusalem. Thus, by the logic where deaths have occurred, the Bishop of Jerusalem should then be the successor of Peter and the primary see. 
Can the Bishop of Rome validly claim to be Peter's successor? Yes, and the Roman church did, and it was unchallenged for the most part and accepted. And by Matthew 16:19 logic, the Church bound this in heaven and earth. However, Rome has no necessary claim to Petrine leadership. Just as the Church allowed Rome to claim that mantle, it can remove it. Although, practically, it would take an extreme emergency to agree that the Bishop of Rome no longer has an intrinsic claim to the papacy.

So . . . Petrine leadership is real, is continuous, it's transferable, and its intrinsic link to Rome all check the necessary boxes.

Luke 24:15 says that Jesus was "taken up into heaven." Mark 16:19 says the same. Acts 1:9 also says, "he was lifted up, and a cloud took him from their sight." Jesus' bodily ascent into heaven is an essential belief in Christianity. The creed states it as one of its propositions: "He ascended into Heaven." 

For clarity, let's see, Acts 1:11 "They said, “Men of Galilee, why are you standing there looking at the sky? This Jesus who has been taken up from you into heaven will return in the same way as you have seen him going into heaven.”" Here it is clear, Just as Jesus is going to one day physically return, so is he ascending into heaven where he will "sit" at the "right hand" of the Father (Rev 3:21; Mt 22:44; Acts 2:33) and the Nicene Creed says, "he is seated at the right hand of the Father."

A lot of things get Christians squeamish about their faith, but one that seems to really get Christians, maybe Catholics in particular, is that Jesus physically ascended into Heaven. Why is this troublesome? Well, for one, the universe is 93 billion light years. That means it would take light that long to travel from one end to the other (or something like that). So did Jesus keep floating up and up and up . . . (if there is an "up" in the universe)? Sure! Or it could have happened in the blink of an eye. The other issue is that this physical bodily ascension seems to imply that Jesus is currently at location (x,y,z), or that Heaven is at that location. Yes. He is at a location, and heaven is at a location. What that means, we can't understand, but he is there, sitting . . . or standing or whatever he is doing.

Some people think that the ascension and the current existence of Jesus is more spiritual than the alternative. But then, what exactly was the point of the resurrection? There is zero point in a resurrection if only two weeks later, he reverts to spiritual form and glides away.

One issue for Catholics is that the current bodily existence of Jesus complicates the Eucharist, the elements of which are the body and blood of Jesus. It is true. Jesus is alive. The Eucharist is not a substitute for his being, person, and presence. All one has to remember is that it was Jesus, who was very much alive, who distributed bread and wine to his disciples and said, "this is my body."

Now, of course, the manner of existence of Jesus, a physical man who is God, is beyond anything we can think or comprehend. So it is not reductive to think of Jesus as a bodily existing man. We only have to give up the parameters of our thinking and rely on faith to make sense of whatever new reality awaits us.

So Jesus is alive. He is resurrected. He is a body and is somewhere. Now . . . so . . . if Jesus is sitting at the right hand of the Father . . . so . . . is the Father . . . 

Is being ethical the same thing as being a good person? Is being a good person the same as being ethical?

Does being religious imply that one will be good and or ethical? I think we can answer this one quickly. No. Being religious does not in itself mean that someone is good or ethical. The proof is in the pudding. Religious people the world over and over the centuries have shown that there isn't a necessary coupling between religiosity and goodness or ethicalness. Many religious people are very good people, but many not very good people are deeply religious. But, perhaps, that's not the point . . . or is it?

Can someone be ethical and not good? Ethics is not easy to define. But it has to do with principles of action, society (however, one construes that), and human flourishing (whether in a broad quasi-eschatological and teleological sense, or whether in an individualistic, granular present sense).

The first problem always is what exactly is good? There are many goods, satisfying hunger, laughing, peace, justice, engaging in fulfilling work, enjoying art, etc. Why are these good and is there an intrinsic ordering to them? Satisfying hunger is good but is undermined if to do so, I take food from someone else who needed that food to satisfy their hunger. So the greater good there would be abundance and solidarity so that there is enough for both of us and it is my aim to ensure we both get to satisfying our hunger and we don't try to hoard the abundance or excess. As we game it out the greater goods become intangible conditions we set so that we can optimize justice, peace, and the like so that we can all share resources fairly.

Ultimately, though, we need to plant our flag on the greatest possible good. Only such a good may be the true north star for any practical earthly conception of good.  Such a good must be a good in and for itself. It cannot be a good in any way dependent on it's utility--how useful or good it is for something. Such a good that is good in itself demands recognition as such and this is what we sense as the holy and the sacred. The Holy is the transcendent good beyond all practical conceptions of good. It is visible in this world, but not of this world, and cannot be accessed as a thing in the world. 

The irony then is it is the religious who necessarily preserve the sense we have the sacred and the holy, even when they fail at being good themselves. Though it then becomes the ultimate scandal when the ones who see the Good as the Holy fall short and bring scandal. Even worse, if goodness in itself is, at its root, distinct from utility, then there's an aspect of holiness that may seem divorced from the practical goods that we all appreciate. For instance, the holy person on their way to pray may be impatience and rude to the person interrupting them. 

The only way those who seek holiness can also reflect ultimate goodness is if they partner with those who seek goodness even at the expense of holiness. It seems like folly to expect any single human to be wholly holy and wholly good (in the practical sense). But as a corporate body of Christians, the tasks can be distributed as long as everyone understands their roles. That those who pursue practical goods understand that they do so at the expense of true devotion to the holy. And those who seek the path of holiness understand that their quest blinds them to the necessary practical goodness that should define the Christian. I suppose, though, in the long run, the true Christian strives not to neglect either holiness or goodness.

Someone once asked me about reading an introduction to the Bible. The book she showed me was a very nice-looking book. I glanced in it, and it looked like it had a lot of really good information. She asked if it would be good. The bible is always good--necessary--to read for one's spiritual journey. However, reading the bible with the aid of academic experts, whether through books, commentaries, etc, is something else. Academically, scripture study is criticism, i.e., it reduces the bible to a combination of history, sociology, and literature. 

(Image--Thomas Waterman Wood 1874)

The world has learned so much from scholars who decided to evaluate the bible, not as a spiritual, divine book, but as a work of history, and also through literary and sociological lenses. The insights have been invaluable in the sense that we can't imagine living in a world prior to this knowledge. In a way, it's like imagining how people could have lived fulfilled lives in the 9th century AD without wifi, books, cars, and hygienic products. But those people lived very full and happy lives, no more or no less than we do. So also, Christians thrived without the burden of this academic approach to scripture.

For some types of Christians, including myself, entering into the world of biblical study with academic experts is a faith-destroying, soul-sucking enterprise. The academic overlay and telescope become a blight and varnish on the scriptures--a maze, a rabbit hole that once you go down, you never get out.

On the other hand, the academic approach to the bible is a major breath of fresh air for many other types of Christians. For one, the bible then makes sense. The cultural context, literary structure, and historical notes categorize things in a neat enough way that remove obstacles to faith.

Everyone needs expert help. Reading the bible is not a solitary thing but a community venture. The scriptures are given first and primarily to the people of faith as a whole, to the Church, and next to us as individuals, in a secondary sense. I think wading into the world of academic "criticism" and context is not the worst thing in the world. But it is eating the forbidden apple. After you enter this world, you can expect to realize that you are naked, you'll start hiding from God, Cain will kill Abel, we build towers to climb to the heavens, and darkness floods in such that God will despair and consider another ark. But in all this darkness, we still get grace, the Messiah, and a savior. What choice do we have? We can't ignore all the insights of the past few hundred years. Yet, we pay dearly for every morsel of this analytical food we eat.

In sum, there has to be an initial time of self-reflection and assessment. It helps to understand what kind of person you are--what kind of Christian you are. Do you lean more toward the affective or more toward the analytical? But ultimately, at the end of the day, there is one real injunction: Fear God and do his commandments. If we stick to this, we can hope to be guided aright.

The agony, trial, and crucifixion of Jesus were no laughing matter. But there seemed to be a significant amount of mocking around his death. First, when Jesus is questioned by Herod, a man who had desired to meet Jesus for so long and see a sign from him, he--Jesus--is mocked.

"[Even] Herod and his soldiers treated him contemptuously and mocked him, and after clothing him in resplendent garb, he sent him back to Pilate.i" (Lk 23:11)

Matthew's account is more graphic:

"27 Then the soldiers of the governor took Jesus into the praetorium, and they gathered the whole battalion before him. 28 And they stripped him and put a scarlet robe upon him, 29 and plaiting a crown of thorns they put it on his head, and put a reed in his right hand. And kneeling before him they mocked him, saying, “Hail, King of the Jews!” 30 And they spat upon him, and took the reed and struck him on the head. 31 And when they had mocked him, they stripped him of the robe, and put his own clothes on him, and led him away to crucify him." (Mt 27:27-31)

It is in the midst of the mocking that Jesus is beaten, spat on, and then given a garment that is later  stripped off him.

At the crucifixion scene, the rulers then sneer at him (Lk 23:35), followed by the soldiers (Lk 23:36), then the inscription, "This is the King of the Jews" (Lk 23:38) is meant to be something of a taunt and mockery, and then there's the one criminal (Lk 23:39).

All these indicate the apparent extent of Jesus' failure. This man who was to be king now hangs here, a spectacle. It does little good to make Jesus over godlike and suggest all the while he had secret knowledge and would, if he could, wink at the camera because he knows what's coming. The abjectness of the failure, such that all this taunting makes sense, must be appreciated.

It is then that we see the faith of Christ in his patience. He had failed, and his kingship and dominion hung on the cross as a spectacle. He responded to none of the taunts. But finally responds to the criminal who reaches out to him in faith. The criminal proclaims Jesus' innocence, which was also apparent to all. He asks Jesus to remember him when he comes into his kingdom. Whatever that meant, it was pure faith that this weak, defeated Messiah still had a kingdom and had the power to save. So when Jesus says, "today you will be with me in paradise," we can understand that that is similarly Jesus' own statement of faith. 

The mockery and taunting of Jesus tell us one thing: that Jesus' kingdom and perceived political aspirations were a real thing. This is what people, even his disciples, expected of him--a kingdom. For Jesus' sacrifice to be really meaningful, he had to feel the full weight of that failure. Thus, the fact that in the lion's den of failure, he declares the salvation of the criminal, is a testament to the faith of Christ.