Hence, we reply, in conclusion to the question presented: That the fundamental, certain mark of the children of God and members of Jesus Christ, is that by virtue of which this appellation belongs to them in truth according to the promise of God, namely, _the only saving faith which worketh by love_; upon which God himself looks with gracious eyes, and which alone avails before him (Gal. 5:6; Jer. 5:3; Hos. 2:2; Jer. 5:1; Acts 8:37; 15:11; Is. 26:2) wherefore we, being one or unanimous with God, must have respect to it alone, seeing that the Lord Christ himself, promising Peter salvation upon his faith and confession, adds: “Thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.” Matt. 16:18. We shall now briefly show, what faith in Christ is, what is to be believed, what its design is, and what are the internal and external operations of faith. This faith in Christ, by which men become partakers of all the acquired benefits of Jesus Christ, is neither an uncertain opinion nor merely a bare confession of the mouth, but a firm and sure confidence of the heart, which doubts not the things promised by God in Christ; but has a firm assurance that he who has promised them is able also to perform them. Heb. 11:13; 3:6; Rom. 10:10; 4:20,21. By this firm and sure confidence the believer in the promises of God is established in Jesus Christ his Savior, because he knows that all the promises of God are yea and amen in him; on which he lays firm hold, as on an anchor of his soul, both sure and steadfast. Acts 10:43; 1 Pet. 1:10,11; John 8:56; Heb. 11:26; 2 Cor. 1:20; Heb. 6:18,19. He believes with his heart that God,--for the fulfilling of his gracious promises, willing to show his great love toward mankind who, through sin, had fallen into death and manifold corruptions, by redeeming them,--sent into this world for this purpose, when the time of all prophecies was fulfilled, his only, dear and beloved Son, who from eternity was with his Father in great glory and beloved by him before the foundation of the world, possessing great riches and being equal with God his Father, by whom all things were made, and without whom not anything was made of all that was made in heaven or upon earth, and in whom they all stand, since he upholds all things by the word of his power. Gen. 22:18; Deut. 8:15; Is. 7:15; 9:6; 11:1; 40:9; Micah 5:2; John 3:16; Rom. 5:8; 9:31; 1 John 4:9,10; Gen. 3:19; Wis. 2:24; 4 Esdr. 7:48; Rom. 4:5,12; 1 Cor. 15:21; Rom. 5:16; 4 Esdr. 3:7; Gen. 3:17; Rom. 1:2; 8:3; Col. 1:13; Eph. 1:7; Gal. 4:4; Mark 12:6; 1:11; Matt. 17:5; 3:17; Heb. 1:8; 7:3; 13:8; 1:3; John 16:28; 17:5,24; 2 Cor. 8:9; Phil. 2:6; Rev. 1:18.