I Corinthians 15:14

your faith . . . vain-- (Co1 15:11). The Greek for "vain" here is, empty, unreal: in Co1 15:17, on the other hand, it is, without use, frustrated. The principal argument of the first preachers in support of Christianity was that God had raised Christ from the dead (Act 1:22; Act 2:32; Act 4:10, Act 4:33; Act 13:37; Rom 1:4). If this fact were false, the faith built on it must be false too.

In this chapter the apostle treats of that great article of Christianity - the resurrection of the dead. I. He establishes the certainty of our Saviour's resurrection (Co1 15:1-11). II. He, from this truth, sets himself to refute those who said, There is no resurrection of the dead (Co1 15:12-19). III. From our Saviour's resurrection he establishes the resurrection of the dead and confirms the Corinthians in the belief of it by some other considerations (Co1 15:20-34). IV. He answers an objection against this truth, and takes occasion thence to show what a vast change will be made in the bodies of believers at the resurrection (v. 35-50). V. He informs us what a change will be made in those who shall be living at the sound of the last trumpet, and the complete conquest the just shall then obtain over death and the grave (Co1 15:51-57). And, VI. He sums up the argument with a very serious exhortation to Christians, to be resolved and diligent in their Lord's service, because they know they shall be so gloriously rewarded by him (Co1 15:58).

15:14-18 If Christ has not risen from the dead, then Christian faith is useless. But in reality, Jesus’ resurrection is proof that the sacrifice of Christ fully atoned for human sins (see 15:3). If Christ has not been raised, then human beings remain unforgiven, under the judgment of God—still guilty of their sins (see Rom 3:19; Eph 2:1-3).