My response: Let’s talk about Romans 1.

Verse
19 says “Because that which is known of God is manifest among them, for
God did manifest it to them,” (Young’s Literal Translation). And the
KJV says, “God has SHOWED it to them.”

Now, why did God have to
MANIFEST/SHOW the unbeliever he exists? Piper says that deep down the
unbeliever already knows that God exists. But Mr Piper! Why would God
bother manifesting his existence again? It would be unnecessary to do
so if the unbeliever already knows. In summary….

1) Piper says that unbelievers “know in the bottom of their hearts that God exists”.
2) He’s basically saying that God is stupid.
3)
Because why would God bother showing/manifesting his existence if
unbelievers already know he exists “deep down” in their hearts?

OK. Let’s leave this point. Next issue.

Think about Adam. Perfect, upright Adam.

God
had to reveal Himself to Adam over and over again in Genesis 1. In
fact, God had to VERBALLY tell Adam the MOST BASIC THINGS about life
like “till the ground”, “multiply”, etc. God also had to reveal the Law
to Adam. So Adam did NOT know about God, the Law or agriculture “deep
down in his heart”. Indeed, man cannot live by bread alone. He needs
God to FEED HIM THE WORD. Even Adam simply could not find out about God
or the Law except God revealed it to him.

And remember. Adam was
innocent. Yet God had to TELL HIM about Himself and His Law (and even
tell him about tilling the ground). Adam therefore did NOT know God
naturally, but God had to REVEAL Himself to Adam.