Now the things which I write unto you, behold, {o} before God, I lie not.

(o) This is a type of an oath.

People's New Testament

1:20 Behold, before God, I lie not. This statement, an important one in view of the declarations of the Judaizers, Paul makes very solemnly.

Jamieson-Fausset-Brown Bible Commentary

20. Solemn asseveration that his statement is true that his visit was but for fifteen days and that he saw no apostle save Peter and James. Probably it had been reported by Judaizers that he had received a long course of instruction from the apostles in Jerusalem from the first; hence his earnestness in asserting the contrary facts.

Matthew Henry's Concise Commentary

1:15-24 St. Paul was wonderfully brought to the knowledge and faith of Christ. All who are savingly converted, are called by the grace of God; their conversion is wrought by his power and grace working in them. It will but little avail us to have Christ revealed to us, if he is not also revealed in us. He instantly prepared to obey, without hesitating as to his worldly interest, credit, ease, or life itself. And what matter of thanksgiving and joy is it to the churches of Christ, when they hear of such instances to the praise of the glory of his grace, whether they have ever seen them or not! They glorify God for his power and mercy in saving such persons, and for all the service to his people and cause that is done, and may be further expected from them.