First of all read your own Scripture the Bible before finding fault with Islam.
Jesus established the death penalty for those who abandon his teachings.
John 15:6 NKJV
If anyone does not abide in Me, he is cast out as a branch and is withered; and they gather them and throw them into the fire, and they are burned.
Yet Christians have abandoned his teaching by drinking alcohol, eating pork etc. but they are not being punished accordingly!
People having no faith shall enter Hell: Deuteronomy 32: 20-23
They have provoked Me to jealousy by what is not God;
They have moved Me to anger by their foolish idols.
But I will provoke them to jealousy by those who are not a nation;
I will move them to anger by a foolish nation.
For a fire is kindled in My anger,
And shall burn to the lowest hell;
It shall consume the earth with her increase,
And set on fire the foundations of the mountains.
I will heap disasters on them;
I will spend My arrows on them.
It is hard for a rich man to enter the Kingdom of Heaven than a camel to go through the eye of a needle: Matthew 29:22-24
Jesus said, "23Then Jesus said to his disciples, 'I tell you the truth, it is hard for a rich man to enter the kingdom of heaven. 24Again I tell you, it is easier for a camel to go through the eye of a needle than for a rich man to enter the kingdom of God."
The wicked and all the nations tht forget God shall be turned to Hell: Psalm 9:17
Kill Followers of Other Religions: Deuteronomy 13:7-12 NAB. If your own full brother, or your son or daughter, or your beloved wife, or you intimate friend, entices you secretly to serve other gods, whom you and your fathers have not known, gods of any other nations, near at hand or far away, from one end of the earth to the other: do not yield to him or listen to him, nor look with pity upon him, to spare or shield him, but kill him. Your hand shall be the first raised to slay him; the rest of the people shall join in with you. You shall stone him to death, because he sought to lead you astray from the Lord, your God, who brought you out of the land of Egypt, that place of slavery. And all Israel, hearing of this, shall fear and never do such evil as this in your midst.
Deuteronomy 17:2-5 NLT Suppose a man or woman among you, in one of your towns that the LORD your God is giving you, has done evil in the sight of the LORD your God and has violated the covenant by serving other gods or by worshiping the sun, the moon, or any of the forces of heaven, which I have strictly forbidden. When you hear about it, investigate the matter thoroughly. If it is true that this detestable thing has been done in Israel, then that man or woman must be taken to the gates of the town and stoned to death.
Death to Followers of other Religions
1) Whoever sacrifices to any god, except the Lord alone, shall be doomed. (Exodus 22:19 NAB)
In 2 Kings 10:18-27, God orders the murder of all the worshipers of a different god in their very own church! In total God kills 371,186 people directly and orders another 1,862,265 people murdered.