Why would Jesus have to die on the cross?

Why would Jesus have to die on the cross?
According to the Christian doctrine, Jesus died on the cross as a sacrifice for our sins. Every human is born with sins, or all humans will eventually sin, and therefore it was necessary that someone as pure as Jesus would be crucified to nullify these sins. The question is; why does anyone have to die for our sins when God, the all merciful, could as easily grant us forgiveness if we asked for it? Why does He have to make someone suffer for our sins or for someone else’s sins? Isn’t that unjust of Him? According to the Bible the way to redemption could be obtained without the need for sacrifice. The Bible says: Ezekiel 18:20 The soul that sinneth, it shall die. The son shall not bear the iniquity of the father, neither shall the father bear the iniquity of the son: the righteousness of the righteous shall be upon him, and the wickedness of the wicked shall be upon him.
Ezekiel 18:21 But if the wicked will turn from all his sins that he hath committed, and keep all my statutes, and do that which is lawful and right, he shall surely live, he shall not die.
Clearly the soul that sins shall die. Clearly, no one shall bear the iniquity (sins) of others. So Jesus cannot bear the sins of others either. If one is righteous then it shall be upon him, and if one commits a sin then it shall be upon him, and not on Jesus. Finally, the way to repentance and forgiveness is by turning from all sins, doing what is right, and keeping the commandments.
Also we see the same message given by Solomon. He says in the book of Ecclesiastes 12:13 "Let us hear the conclusion of the whole matter: Fear God, and keep his commandments: for this is the whole duty of man." This is the whole message, and this is the conclusion of messages. It is that one should fear God, keep His commandments, and nothing else.
Again in II Chronicles 7:14 "If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land." This clearly states that to seek forgiveness from God we have to humble ourselves, pray, seek God, and turn away from wickedness.
Finally the Bible says in I Samuel 15:22 "And Samuel said, Hath the LORD as great delight in burnt offerings and sacrifices, as in obeying the voice of the LORD? Behold, to obey is better than sacrifice, and to hearken than the fat of rams." This clearly states that obeying God is better than sacrifice whether this sacrifice is of objects, animals, or humans, or any other type. What God likes is for us to heed and obey Him, and if that is what God likes then it is not of Him to come later and change His mind and His ways. God says in the Holy Quran, "Verily God is All-Knowing, All-Wise" (Ch 9: Vr 28).
Now that we have seen this, Christians say that Jesus has changed some of these laws. Did Jesus come to change laws? Let’s look at what Jesus says. In Matthew 5:17 "Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil." Jesus clearly states that he was not sent to abolish the law, the law of which had already existed. What is mentioned above cannot be discounted. Then Jesus continues to say, in Matthew 5:18 and 19 "For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled. Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven." Jesus here asserts that not even as much as a tittle (dot) shall pass from the law. Every thing is kept the way it was. This is why the previous laws cannot be removed or discarded, and those who willfully change these laws "he shall be called the least in the kingdom of heaven."