“If common grace is not sufficient for a person not to commit a single sin in their life, then can they be judged for it?”
This is part of the classic argument: The problem of evil.
Romans 9:19, 20,
"You will say to me then, “Why does he still find fault? For who can resist his will?” But who are you, O man, to answer back to God? Will what is molded say to its molder, “Why have you made me like this?”
I would start by saying that "Common Grace ‘’ would be better understood–at least the way you are using it–as Common Morality (could be thought of as restraining, governing, actionable morality).
Typically_ grace is needed after sin. It does not keep us from any sin per se.
The Common Morality is available because of …
Humankind being actively restrained by God. God restrains us from all of the evil we are capable of by actively holding us back from sin (cf., Romans 1:24, 26, 28).
Every human has been given a conscience by God. God, to govern them, and give each one a proper standard of right-and-wrong (cf., Romans 2:14-16).
Humankind is given common knowledge of God by God. Common fear of God through General Revelation (the universal, basic understanding of God) that all are responsible for. There are extreme consequences for not responding with elementary thankfulness and fear (e.g., being given over to more sin and the embracing of lies, exchanging truth for lie) (cf., Romans 1:18-21).
It will take God to judge the totality of His revealed and unrevealed truth in regard to judging each individual (whether lost or saved). Only He could ever hold all of His truth without partiality and in perfect balance without conflict.
As Christians, we have a corrupted, sinful part—the flesh—and yet a partially restored, perfect part. We have the mind of Christ, but not fully yet (cf., 1 Corinthians 2:16; Romans 11:33-36).
We have limited scope, permission and abilities to know all there is to know about God’s salvific purposes. We can ask questions about theology that are unanswerable because God has withheld vital information from us. This gap in revelation makes the hardest questions in the Christian experience hard to answer concretely. We are extremely finite in our understanding and especially so when compared to a God who created the known universe.
The core answer to your summarized question is extremely complex and has several layers and complexities. Furthermore, the core answer has tensions that are difficult to synthesize. These tensions have displeased many a man throughout time. God doesn’t seem bothered by it. :-)
One argument that many do not like is inherited sin. When Adam sinned we sinned.
“For God has consigned all to disobedience, that he may have mercy on all.”
God has revealed Himself to all people throughout all time
Psalm 19:1-4a
"The heavens declare the glory of God,
and the sky above proclaims his handiwork.
Day to day pours out speech,
and night to night reveals knowledge.
There is no speech, nor are there words,
whose voice is not heard.
Their voice goes out through all the earth,
and their words to the end of the world.
All people choose to accept of reject Creator God
Roman 1:18-23
For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse. For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. Claiming to be wise, they became fools, and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.
The Conscience / We know we are Sinning (i.e., Specific Revelation)
Roman 2:12-16
For all who have sinned without the law will also perish without the law, and all who have sinned under the law will be judged by the law. For it is not the hearers of the law who are righteous before God, but the doers of the law who will be justified. For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them on that day when, according to my gospel, God judges the secrets of men by Christ Jesus.
Although we sin from childhood, we instinctively know it is wrong from childhood.
Proverbs 9:10
The fear of the LORD is the beginning of wisdom, and the knowledge of the Holy One is insight.
Psalm 25:14
The friendship of the LORD is for those who fear him, and *he makes known to them his covenant.
Conclusion: There are responsibilities for all in regard to General Revelation, Specific Revelation, and the Natural Law, etc.
Genuine Ignorance is Taken into Account
John 9:41, "Jesus said to them, “If you were blind, you would have no guilt; but now that you say, ‘We see,’ your guilt remains.
Romans 9:14:20
What shall we say then? Is there injustice on God’s part? By no means! For he says to Moses, “I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.” So then it depends not on human will or exertion, but on God, who has mercy. For the Scripture says to Pharaoh, “For this very purpose I have raised you up, that I might show my power in you, and that my name might be proclaimed in all the earth.” So then he has mercy on whomever he wills, and he hardens whomever he wills. You will say to me then, “Why does he still find fault? For who can resist his will?” But who are you, O man, to answer back to God? Will what is molded say to its molder, “Why have you made me like this?”