+I. By the undoubted truthfulness of his statements.+--"Now the things which I write unto you, behold, before God, I lie not" (ver. 20). The assertions of the apostle flatly contradicted the allegations of his enemies. They insinuated that Paul was but a messenger of the authorities of the Church at Jerusalem, and that all he knew of the Gospel had been learned from the twelve. So far from this being the case it is evident that for several years he had been preaching the Gospel, and had not seen any of the twelve, except Peter and James, and that only for a fortnight at Jerusalem about three years after his conversion. "In the present case," remarks Professor Jowett, "it is a matter of life and death to the apostle to prove his independence from the twelve." Having said all he can to substantiate his point, he concludes by a solemn appeal to God as to his veracity: "Behold, before God, I lie not." The apostle never makes an appeal like this lightly, but only in support of a vital truth he is specially anxious to enforce (Rom. ix. 1; 2 Cor. i. 17, 18, 23; 1 Thess. ii. 5). "When fiction rises pleasing to the eye; Men will believe, because they love the lie; But truth herself, if clouded with a frown, Must have some solemn proof to pass her down."--_Churchill._ The vigorous and faithful maintenance of the truth brings glory to God. +II. By his evangelistic activity.+--"Afterwards I came into the regions of Syria and Cilicia" (ver. 21). During this tour very probably the Churches were founded, referred to in Acts xv. 23, 41. "A man's work," says George Macdonald, "does not fall upon him by chance, but it is given him to do; and everything well done belongs to God's kingdom, and everything ill done to the kingdom of darkness." God is the sublime end of all human activity, and our powers can never be more nobly employed than in expounding His will, unfolding His gracious character, advancing the interests of His kingdom, and striving to promote His glory among the children of men. Man is never so great, so luminous, so grand as when he is doing work for God with the light and help of God; and all such work is a revelation of the character and purposes of God open to the eyes of all who will see.