Observe here, 1. That though St. Paul did not put confidence and trust in his sincerity and Christian grace, yet he did rejoice, and holily glory, in the evidence of his grace, and in the testimony of a sincere and upright conscience: Our rejoicing is this.
Learn hence, That an holy glorying and rejoicing in the grace of God, which upon good and sufficient grounds we find evident in ourselves, is lawful and allowable. A Christian may and ought to rejoice not only in the confidence of Christ's merits, but also in the conscience of his own sincerity.
Observe, 2. The particular grace evidence, which the apostle took comfort in: his sincerity and godly simplicity; that is, his uprightness both of heart and life, his freedom from guile and hypocrisy.
Thence note, That the conscience of sincerity is such a crown of rejoicing, as will support a Christian's spirit under and against the greatest difficulties which may arise in any condition. This sincerity discovers itself in its acting by a right rule, from a right principle, and to a right end; and it supports a man's spirit in the duty of prayer under the burden of slander and reproach, in the dark night of affliction, in the disconsolate hour of death, and at the dreadful day of judgment.
Observe, 3. That it is not a single act of sincerity, but a constant course of upright walking, that our apostle rejoiced and took comfort in: We have had our conversation in the world in all simplicity and godly sincerity. It is not a single action, but a series of good actions, that administers comfort: as God doth not judge of our state and condition by a particular action, no more should we, but by the general bent of our resolutions, and the constant course and tenor of our conversations: Our rejoicing is this, that by the grace of God we have had our conversation in the world.