Now the things which I write unto you
Concerning his education, his religion, his principles and practices before conversion; concerning his call by the grace of God, the revelation of Christ in him, and his preaching of him among the Heathen; concerning his travels to several places for this purpose, and especially concerning his not receiving the Gospel from men, not from any of the apostles; and how that upon his conversion he did not go up to Jerusalem to any of them, to be taught and sent forth by them; and that it was not till three years after that he wept thither to see Peter, with whom he stayed but fifteen days, and saw no other apostle, but James the Lord's brother. Now this being a matter of moment, and what he had been charged with by the false teachers, that the Gospel he preached he had received from men, in order to disqualify him and bring him into contempt as an apostle, and which they had insinuated to the Galatians; he therefore not only wrote these things, but for the confirmation of them solemnly appeals to God the searcher of hearts for the truth of them;
behold, before God I lie not;
which is not only a strong asseveration, but a formal oath; it is swearing by the God of truth, calling him to be witness of the things that he had written; whence it is manifest that an oath upon proper occasions, where there is a necessity for it, and a good end to be answered by it, may be lawfully made.