Then God said, “Take your son, your only son, Isaac, whom you love, and go to the region of Moriah. Sacrifice him there as a burnt offering on one of the mountains I will tell you about.” Genesis 22:2

God does not ask anything from us that He is not willing to do himself. God had no intention of allowing Abraham to go through with this sacrifice, but He wanted it to be a spiritual marker in Abraham’s life.

It proved the trust Abraham had in God. Abraham was ready to surrender the one thing he waited eighty years to have. . .Isaac.  The writer of Hebrews believes Abraham was willing to sacrifice God because God could bring Isaac back from the dead.

By faith Abraham, when God tested him, offered Isaac as a sacrifice. He who had received the promises was about to sacrifice his one and only son, even though God had said to him, “It is through Isaac that your offspring will be reckoned.” Abraham reasoned that God could raise the dead, and figuratively speaking, he did receive Isaac back from death.  Hebrews 11:17-19

That's faith!
It also proved that God was more important in Abraham’s life than this son. We can allow the things of this earth to take precedent over God and make our decisions in life based on our children, our job, our house, etc. It is best for us to see everything in this world through God’s eyes and priorities first.

It laid the foundation for the future sacrifice of Jesus Christ. Thousands of years later, on this same mountain, God would offer His Son up as a sacrifice, this time allowing the execution to follow through, providing the ultimate sacrifice for all mankind.