> I think that Abraham was willing to sacrifice Isaac because he knew that
> God would raise him from the dead, because God promised that a nation
> would come from Isaac and from this seed would come blessings to the
> nations, and God had always been faithful.
As well you should! From Hebrews 11 (NIV):
17 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,
18 even though God had said to him, "It is through Isaac that your
offspring will be reckoned." 19 Abraham reasoned that God could raise the
dead, and figuratively speaking, he did receive Isaac back from death.