Dr. Thomas Manton, on 2 Peter 1:4: It is an instance of God’s love, that he will deal with us in the way of promises. The world is depraved by sin, and sunk into fears and despair of any good from God, whom we have so highly provoked. Therefore God invites and allures us to himself by promises; for promises are declarations of God’s will in the gospel, whereby he signifies what good he will freely bestow us, if we will look after it. … A promise is more than a purpose; for the purpose and intention of a man is secret and hidden in his own bosom, but a promise is open and manifest. Thereby we get the knowledge of the good intended to us. If God had only purposed to bestow all his grace upon us, we could not have known his intention and purpose till it were manifested in the effect; it would have been as a hidden treasure or sealed fountain, of no comfort and encouragement to us till we had found it. But now the word is gone out of his lips, we may know how we shall speed, if we will hearken to his counsel. God’s promises are, on his part, the eruption or overflow of his love. His heart is so big with thoughts of good to us, that his love cannot stay till the accomplishment of things, but he must tell us aforehand: Isa. 62:9, ‘Before they spring forth, I tell you of them.’ He might have done us good, and given us no notice; but that would not satisfy him. It is an obligation God takes upon himself: promittendo, se debitorem fecit. God’s purposes are unchangeable, but promises are a security put into our hands, not only give us notice, but assurance that thus it shall be. We have the greater holdfast upon him, and may put his bond in suit: Ps. 119:49, ‘Remember the word unto thy servant, upon which thou hast caused me to hope.’ The whole sermon, which unites brevity to its other excellences, can be read here.