NOTES for Joh 1:12
What means "to become sons of God"? And which power is necessary to become them? At the dawn of the Jewish history, in the days of the Exodus and in the time of the conquest of Palestine, everything was simple. Then was called son of God every Hebrew, who belonged to the people of God by being born Hebrew. But even in this period to be Hebrew not only meant belonging to the Jewish people by birth, but also keeping this union-covenant, which was concluded on Sinai, and thus, to observe also the Torah given to the people by Moses. With time the glance on the Torah and on the people changed, and the question to know who is the son of God, began to be solved in the context of the observation of any tradition inside yahvistes communities. It was obvious that it is about yahvistes believers, and not about heathen, who at the pre-captivity era were enough among the Jews.
But already in this pre-captivity era, inside the community were formed (mainly around the prophets) movements, members of which were considered as sons of God, first of all, each other and its members. During the captivity and at the after captivity period, when appeared the Synagogue, its members began to consider themselves sons of God. Here already, it was of course not only and not so much about nationality (could join the Synagogue those who had no relationship by blood with the Jewish people), than about the loyalty of the community, and thus, and the traditions connected with this community. The tradition also supposed the communion with God (prayer, reading and study of the holy texts), and the raising and education activity (the study of the Torah and its teaching to children and adults), and works of charity. All this made of man, as the scientific rabbis of the time of the Second Temple said, son of God. It is not by chance that in the evangelic time to that title claimed, above all the Pharisees - the members of the religious brotherhoods, participating actively in all which was enumerated.
They were sure that they can really consider themselves sons of God: because they all succeeded in God's works, since they understood them, as nobody else. But the early Christian Church emphasizes not on the religious activity, nor any other activity, but on this life of the Kingdom, which is impossible without Christ. Of course the activity connected to the works of charity or the religious teaching, does not negate it, but brings in the foreground another: communication with the risen Christ and this unity of the life of the Kingdom, which unites His faithful with Him, making them, according to the words of the apostle Paul, "the body of Christ". It is not surprising: because Christianity is nothing else than the life with Christ in His Kingdom. All the rest is just consequence.