It is important to read the Scriptures studiously with an eye for context as well as sensing the intent of the author. The ending of Galatians 3 is often dismissed as merely saying that Paul is saying that all could come to Jesus. But anyone always could come to become Jews and honor God through the Law. There was never any restriction on who could or could not come to believe in the God of the Jews. There were never any restriction on who could believe in the coming Messiah. Even the despised Samaritans looked forward to the Messiah. In fact around the time of Jesus, Herod’s Temple (destroyed in 70AD) had a huge outer court specifically for believing gentiles.
What Paul was saying is that everyone, by the Spirit (Gal. 3:1-4) in Christ would be full inheritors and full heirs according the promise to Abraham, based on faith. This would effectively remove all the walls and divisions that the Law and the Jews on their own raised between people. In Herod’s temple unlike the earliest temples, there were dividing walls between women, gentiles and unblemished Jewish males. Unmaimed Jewish males were the only ones who could come into the court area outside where the priests served. Only Levitical priests were allowed in the first outer court and the inner court. Only the High Priest was allowed in the Holy of Holies.
In Ephesians and in Hebrews we are told that all can safely approach the throne of God (the Holy place), and that all are recipients of the most Holy Spirit of God. No more walls of restrictions and limitations. All are to be full inheritors. The Law and its divisions, as well as the Jewish leaders and their added divisions are of no more consequence. Through Christ faith has come and our differences though still there, no longer matter. It is the Holy Spirit who will decide who is to have what gifts and ministries (1 Cor. 12). We are no longer ‘under guard’ or ‘under a tutor’. There is only one High Priest to be in our lives and that is Christ who now sits at the right hand of the Father.