God is the one true judge.
Judging another condemns yourself. God will lead one through long suffering for him to reach repentance and bring him closer to God whether this is through suffering or rewards.
2:12 Those who don’t know Christ won’t be judged but those who do will.
He talks of how the law is written, but, also, people have the law written in their hearts.
Jesus and the Law
One of the major laws in the Old Testament deals with circumcision. Paul uses circumcision in both the literal text and as symbolism throughout Romans.
He condemns Jews who condemn Gentiles (non Jews) who aren’t circumcised but are obedient to God.
He condemns those who pass judgment while they do the very things they themselves condemn.
Circumcision takes a double meaning here-don’t condemn the uncircumcised while they are in their hearts obeying God.
Paul says that while they’re (the Gentiles) physically not circumcised, by accepting the faith of Christ and being obedient to His word, they are Holy (circumcised in their hearts and souls).
This was a bold statement back in those days with Christianity being very new and the Old.