What does Romans 3:29 mean?

Paul knew that some religious Jews would object to what He was writing. Many still believed they would not be judged by God for their own personal sin because they were circumcised and followed the law—because they were law-observant Jews. Paul has carefully dismantled the logic behind that belief. First, nobody can follow the law perfectly, which means nobody can be deemed righteous in God's eyes on the basis of the law (Romans 3:10). Second, God holds all people to the same moral standards, since He gives all people an opportunity to recognize and seek Him (Romans 1:18–20).

Now Paul continues with two questions: Is God only the God of the Jews? Many Jews throughout Israel's history may have said yes to that question. Paul says "No, God is also the God of the Gentiles—the non-Jews." He is the only God, after all. All people must answer to Him. Therefore, it makes sense that God's perfect, ultimate, righteous judgment would carry the same standards for all people.