Abraham believed God and it was credited to him as righteousness(Genesis 15:6):
"For what saith the Scripture? Abraham believed God
and it was counted unto him for righteousness" (Romans 4:3).
"Now to him that worketh is the reward not reckoned
of grace, but of debt" (Romans 4:4).
"But to him that worketh not, but believeth on Him that
justifieth the ungodly, his faith is counted for righteousness" (Romans 4:5).
God told Abraham to offer up his only son as a burnt offering (Genesis 22:2):
"Thine only son Isaac, whom thou lovest"
(Genesis 22:2).
"By Myself have I sworn, saith the LORD, for because
thou hast not withheld thy son, thine only
son" (Genesis 22:16).
Abraham believed that God was able to raise
up Isaac, even from the dead(Hebrews 11:19):
"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"(Genesis 22:5).
Isaac was a type or picture of our Saviour(John 3:16):
"He is brought as a lamb to the slaughter" (Isaiah 53:7).
"Yet it pleased the LORD to bruise Him" and
to "make His soul an offering for sin" and to "prolong His days" (Isaiah 53:10).
"He shall see the travail of His soul, and shall
be satisfied: by His knowledge shall My Righteous Servant justify many; for He shall bear their iniquities"
(Isaiah 53:11).