Gen 22:1 And it came to pass after these things, that God did tempt Abraham, and said unto him, Abraham: and he said, Behold, here I am.
Gen 22:2 And he said, Take now thy son, thine only son Isaac, whom thou lovest, and get thee into the land of Moriah; and offer him there for a burnt offering upon one of the mountains which I will tell thee of.
Gen 22:3 And Abraham rose up early in the morning, and saddled his ass, and took two of his young men with him, and Isaac his son, and cleaved the wood for the burnt offering, and rose up, and went unto the place of which God had told him.

This was probably the hardest thing Abraham ever had to do. Yet we will see why God used this method to test Abraham. After Abraham waited for years to the promised son to finally come, God wants to take the son away.

This is what is said of this incident in the book of Hebrews:

Heb 11:17 By faith Abraham, being tried, offered up Isaac: yea, he that had gladly received the promises was offering up his only begotten son;
Heb 11:18 even he to whom it was said, In Isaac shall thy seed be called:
Heb 11:19 accounting that God is able to raise up, even from the dead; from whence he did also in a figure receive him back.

Abraham had to believe in the resurrection here and believed that God could raise his son from the dead. This showed the saving faith of Abraham. He believed and his faith was counted for righteousness.  It didn't matter about his former mistakes and fears, Abraham was saved by faith and his faith pleased God. 

Gen 22:4 Then on the third day Abraham lifted up his eyes, and saw the place afar off.
Gen 22:5 And Abraham said unto his young men, Abide ye here with the ass; and I and the lad will go yonder and worship, and come again to you.

Abraham could not allow anyone to go with him for that would probably have tried to stop him. He didn't need anyone to hinder his faith or his purpose. I wonder if Abraham thought he imagined the whole thing and had doubts during those three days.

Gen 22:6 And Abraham took the wood of the burnt offering, and laid it upon Isaac his son; and he took the fire in his hand, and a knife; and they went both of them together.
Gen 22:7 And Isaac spoke unto Abraham his father, and said, My father: and he said, Here am I, my son. And he said, Behold the fire and the wood: but where is the lamb for a burnt offering?
Gen 22:8 And Abraham said, My son, God will provide himself a lamb for a burnt offering: so they went both of them together.

Notice also how Isaac was submissive and trusted his father at this point.

Gen 22:9 And they came to the place which God had told him of; and Abraham built an altar there, and laid the wood in order, and bound Isaac his son, and laid him on the altar upon the wood.

There are many hints and prophecies in the Old Testament to the coming of one who would crush the head of Satan. The first prophecy of the seed of the woman coming was to Adam and Eve. Eve may have thought Cain was this promised one. They may have known that whoever it was would have to die but then be resurrected. Abraham knew that Isaac was special and chosen of God. Perhaps with his limited understanding, he may have known of the coming Messiah's death and resurrection but thought it was Isaac himself instead of one to come from his seed. It may explain why Abraham went along with this sacrifice. Perhaps also he was just being obedient to God. Abraham in either case was willing to sacrifice his own son to God perhaps thinking that this sacrifice would make the way of salvation for the whole world.

Whatever the case may have been, this is a picture of what was to come. God was going to send His own Son, Jesus (Yeshua) to die for the sins of the whole world. He chose Isaac to send this promised Messiah to save all who believe in this promised one. Faith in Jesus saves us from sin.  Sin is what condemns us to eternity in hell.  Sin is what we need to be saved from.  If we die without Christ, we die in sin.  The sin will destroy our souls.  That is why Jesus came to save us from sin.  

Gen 22:10 And Abraham stretched forth his hand, and took the knife to slay his son.
Gen 22:11 And the angel of the LORD called unto him out of heaven, and said, Abraham, Abraham: and he said, Here am I.
Gen 22:12 And he said, Lay not thine hand upon the lad, neither do thou any thing unto him: for now I know that thou fearest God, seeing thou hast not withheld thy son, thine only son from me.

God would not allow Isaac to be slain because He was going to use the seed of Isaac to send His own Son.

Gen 22:13 And Abraham lifted up his eyes, and looked, and behold behind him a ram caught in a thicket by his horns: and Abraham went and took the ram, and offered him up for a burnt offering in the stead of his son.

This was a temporary offering until the time came when the perfect sinless sacrifice would be given at Calvary.

Gen 22:14 And Abraham called the name of that place Jehovah-jireh: as it is said to this day, In the mount of the LORD it shall be seen.

Jehovah-jireh means that the Lord will provide. In the fullness of time, God did provide the way of salvation by sending His own Son instead of Isaac. God came into the flesh and became one of us to save us from sin. Isaac was a good man but he could not have been the a perfect sinless sacrifice. It had to be God Himself in the person of His own beloved Son. How awesome to think of this.

Gen 22:15 And the angel of the LORD called unto Abraham out of heaven the second time,
Gen 22:16 And said, By myself have I sworn, saith the LORD, for because thou hast done this thing, and hast not withheld thy son, thine only son:
Gen 22:17 That in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heaven, and as the sand which is upon the sea shore; and thy seed shall possess the gate of his enemies;

This is a promise that will be fulfilled after the times of the Gentiles and the gospel has gone forth into the entire world.

Gen 22:18 And in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice.

This promised seed of Abraham is none other than Jesus Christ who will bring salvation to other nations as well as Israel.

Gen 22:19 So Abraham returned unto his young men, and they rose up and went together to Beer-sheba; and Abraham dwelt at Beer-sheba.
Gen 22:20 And it came to pass after these things, that it was told Abraham, saying, Behold, Milcah, she hath also born children unto thy brother Nahor;
Gen 22:21 Huz his firstborn, and Buz his brother, and Kemuel the father of Aram,
Gen 22:22 And Chesed, and Hazo, and Pildash, and Jidlaph, and Bethuel.
Gen 22:23 And Bethuel begot Rebekah: these eight Milcah did bear to Nahor, Abraham's brother.
Gen 22:24 And his concubine, whose name was Reumah, she bore also Tebah, and Gaham, and Thahash, and Maachah.

When Abraham hears this news he plans to provide a bride for Isaac among his kin. Thus is will fulfill the promise of the seed of Isaac blessing the whole world.

Genesis 23