“Why Peter did not hang himself as did Judas ?”
Matt. 27:5 “And he cast down the pieces of silver in the temple, and departed, and went and hanged himself.”
The easy way to respond to this question would be to say “No one knows.  Any answer to this question would be pure speculation.”  If we delve deeper, however, we see certain principles in this question that can help us in our pursuit of the kingdom of God.  First, we must ask the question why did Judas betray Christ?  We know that there had to be one to betray Christ in order for that which was prophesied to come to pass.  Did Judas know that he himself was the one which would betray Christ?  No!  Judas had no forethought that he would be chosen as one of the disciples, then be the one to betray Christ Himself.  Also, Judas’ name is not mentioned at all in the Law and the Prophets.  So what is it that Judas represents?  Paul addresses this question in his letter to the Romans:
Romans 9:16 So then it is not of him that willeth, nor of him that runneth, but of God that sheweth mercy.  17 For the scripture saith unto Pharaoh, Even for this same purpose have I raised thee up, that I might shew my power in thee, and that my name might be declared throughout all the earth. 18 Therefore hath he mercy on whom he will have mercy, and whom he will he hardeneth.  19 Thou wilt say then unto me, Why doth he yet find fault? For who hath resisted his will?  20 Nay but, O man, who art thou that repliest against God? Shall the thing formed say to him that formed it, Why hast thou made me thus?  21 Hath not the potter power over the clay, of the same lump to make one vessel unto honour, and another unto dishonour?
The New Life Version reads as follows: Romans 9:16 These good things from God are not given to someone because he wants them or works to get them. They are given because of His loving-kindness.17 The Holy Writings say to Pharaoh, “I made you leader for this reason: I used you to show My power. I used you to make My name known over all the world.” 18 So God has loving-kindness for those He wants to. He makes some have hard hearts if He wants to.  19 But you will ask me, “Why does God blame men for what they do? Who can go against what God wants?” 20 Who are you to talk back to God? A pot being made from clay does not talk to the man making it and say, “Why did you make me like this?” 21 The man making the pots has the right to use the clay as he wants to. He can make two pots from the same piece of clay. One can have an important use. The other one can be of little use.
The key to this passage is that God chooses how he will utilize his creation.  From the same lump, mankind, one vessel can be made unto honour, or great use, and another unto dishonour, or little use.  The vessels themselves don’t even know their own use!  In our finite minds, what seems to us to be great use, may in reality be of very little use.  This is why it is important for us to discern spiritually what is happening.  What looks to be a great work in the flesh may in truth be no work at all; conversely, what appears to be futility in the flesh God may be doing to accomplish his will.  In truth, both Peter and Judas betrayed Christ.  Both fulfilled prophecy.  Yet, both responded differently to their actions.  Peter was chosen to be a vessel unto honour by God.  It was because of Peter’s preaching that 3,000 were added to the church.  The humbling truth is that we don’t know how our lives will unfold.  We can say with our mouths that we love God, and like Peter we may boast that we would never betray Him, but what happens when we approach that crossroad?  Is it possible that our utter failure in that moment can be used to fulfill God’s will?  Then, how do we respond?  Do we respond in the flesh, or do we humbly bow ourselves and ask for forgiveness from the ever merciful God?  Judas responded in the flesh, and judged himself, while Peter grieved but continued to press forward in spirit.  In truth, we can learn a great lesson from this question.  Our humanity will continue to fail us and fail God until the day our bodies expire.  Yet, we must persist in spirit to press toward the mark of the high calling in Christ Jesus.  This is why we must, on a daily basis, do our very best to crucify our flesh, in order that God may be able to use us to accomplish his will. For only God knows who was created as vessels of honour and vessels of dishonour.