Our apostle had proved in the foregoing verse the constancy of his own doctrine which he preached from the immutabilithy and constancy of Christ, the subject of it. Here he proveth Christ to be unchangeable, in that all the promises which God hath made to us are fulfilled both in him and by him. All the promises of God in him are yea, and amen; that is, verified and fulfilled in him, and confirmed by him to us.
Learn, 1. That God has made promises, many promises to his people.
2. That all the promises which God has made to his people, are made in Christ, and ratified by him. Christ acts the part and office of a surety; he undertakes and engages for God, that all which he hath promised shall be made good to us.
Learn, 3. That the promises made by God, and ratified and confirmed in Christ, do all tend to the glory of God. They show the sovereignty of his grace, in making promises to his creatures of mercy, who deserved nothing but flaming vengeance and implacable fury. They show the amplitude of his grace; for if grace did not flow abundantly from the heart of God towards us, we could never have received so large a stock of promises from him. Let us then glorify God, by setting a just value upon his promises, as the unchangeable assurance of his love and grace.