If unregenerate man can never seek God according to Romans 3, how could Adam respond to God's questions in the Garden following the Fall (Genesis 3)?
We suspect you have misunderstood the biblical principle of total depravity. The theological principle of total depravity holds that, as a consequence of the Fall of Man, every person born into the world is enslaved to the service of sin as a result of their fallen nature and, apart from the grace of God, is utterly unable to choose to follow God, refrain from evil, or accept the gift of salvation as it is offered.
On the other hand, the doctrine of total depravity does not deny God’s ability to interact with fallen man. God may reveal Himself to fallen man without also regenerating a man’s soul so that the unregenerate man still acknowledges and responds to God without necessarily coming to a saving knowledge and trust in God.
God is often seen in scripture to interact with fallen man either by theophanies or through His prophets. These encounters do not necessarily require that God regenerating the person as a result of this contact. Examples in scripture include Cain, Hagar and Ishmael, the Pharaoh, Cyrus of Persia, Nebuchadnezzar, the kings of the northern Kingdom of Israel and others.
Though God made Himself known to these unbelieving people, nevertheless there is no indication they repented and came to saving faith. Though God made Himself known to their flesh, He did not apparently make Himself known to their spirit so as to bring them to faith (though arguably Hagar and Nebuchadnezzar were regenerated).
When God encountered Adam in the Garden, He spoke to Adam as a fallen, depraved man, and Adam responded as a sinful man – not in repentance but by blaming God and Woman for his own sin. Nevertheless, God in His grace chose to regenerate Adam as evidenced by Adam’s repentance (listen to Lesson 3D of our Genesis Bible study to understand how we know Adam was regenerated).
Even after the Fall, God was still interacting with an unbelieving Cain in Genesis 4, and even though Cain responded to God, nevertheless God left Cain in his sin. Though Cain spoke with God, he never gained saving faith. As Paul explains in Romans 1, original sin blinded Cain to the truth of God such that Cain could acknowledge God’s existence while never trusting in God’s promises, as Paul explains in Romans:
Rom. 1:21 For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their speculations, and their foolish heart was darkened.
Rom. 1:22 Professing to be wise, they became fools,
Rom. 1:23 and exchanged the glory of the incorruptible God for an image in the form of corruptible man and of birds and four-footed animals and crawling creatures.
Therefore, unregenerate man is capable of experiencing an encounter with God when God chooses to reveal Himself (as in the case of Cain), but such an experience does not necessarily lead to regeneration. Even after such an encounter, the person may remain spiritually dead in their sins. As James says, simply acknowledging God’s existence is not equal to regeneration:
James 2:19 You believe that God is one. You do well; the demons also believe, and shudder.
Therefore, God may reveal Himself to fallen man in a limited sense from time to time yet still leave the person lost in their sin.