“It is here to be observed that the promises made to Abraham are first made to Christ, and then in Christ to all that believe in Him, be they Jews or Gentiles. This conclusion is of great use. First, by it we learn the difference of the promises of the law and the gospel. The promises of the law are directed and made to the person of every man particularly. The promises of the gospel are first directed and made to Christ, and then by consequent to them that are by faith engrafted into Christ.
Secondly, by this we learn to acknowledge the communion that is between Christ and us. Christ as mediator is first of all elected, and we in Him. Christ is first justified, that is, acquit of our sins, and we justified in Him. He is heir of the world, and we heirs in Him. He died upon the cross, not as a Private person, but as a public person representing all the elect; and all the elect died in Him and with Him. In the same manner they rise with Him to life and si at the right hand of God with Him in glory.
Thirdly, here we see the ground of the certainty of perseverance of all them that are the true children of God. For the office of Christ to which He is set apart is to receive the promise of God for us and to apply it unto us. And this work is done by Christ without impediment and without repentance on His part. The seal and foundation of our salvation is this: that God accepts and knows us for His (2 Tim. 2:19), and that which concerns us is that we must worship God in Spirit and truth and depart from iniquity.
Lastly, here is comfort against the consideration of our unworthiness. You say you are unworthy of the mercy of God, and therefore have no hope. And I say again: Do you truly exercise yourself in the spiritual exercises of faith, invocation, repentance? Be not discouraged. You must not receive the promise immediately of God, but Christ must do it for you. Though you are unworthy, yet there is dignity and worthiness sufficient in Him. If you say, that you must at the least receive the promise at the hand of Christ, I add further that ‘He will not quench the flax that doth but smoke, neither will He break the bruised reed.’ He accepts the weak apprehension, if it be in truth. And our salvation stands in this, not that we know and apprehend Him, but that He knows and apprehends us first of all.”