1 Corinthians 15:1 Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand;
15:2 By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain.
The gospel is that Christ died for our sins, was buried, and rose again. Christ died in our place, and paid the full penalty for our sin. He rose again for our justification. When we believe the gospel, when we trust Jesus, and the gospel for our salvation; we are saved unto eternal life.
The gospel does indeed save us to eternal life; but, when Paul says in verse 2, "ye are saved, if ye keep in memory what I preached unto you", he is not saying, that if you do not keep this in memory, you are lost and going to hell.
Paul is saying, in this passage, that you are saved from the error of false doctrine.
Below is the error Paul was correcting.
1 Corinthians 15:12 Now if Christ be preached that he rose from the dead, how say some among you that there is no resurrection of the dead?
15:13 But if there be no resurrection of the dead, then is Christ not risen:
15:14 And if Christ be not risen, then is our preaching vain, and your faith is also vain.
15:15 Yea, and we are found false witnesses of God; because we have testified of God that he raised up Christ: whom he raised not up, if so be that the dead rise not.
15:16 For if the dead rise not, then is not Christ raised:
15:17 And if Christ be not raised, your faith is vain; ye are yet in your sins.
Paul was saving the body from the error of the teaching that would deny the resurrection.
15:2 By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain.
The gospel is that Christ died for our sins, was buried, and rose again. Christ died in our place, and paid the full penalty for our sin. He rose again for our justification. When we believe the gospel, when we trust Jesus, and the gospel for our salvation; we are saved unto eternal life.
The gospel does indeed save us to eternal life; but, when Paul says in verse 2, "ye are saved, if ye keep in memory what I preached unto you", he is not saying, that if you do not keep this in memory, you are lost and going to hell.
Paul is saying, in this passage, that you are saved from the error of false doctrine.
Below is the error Paul was correcting.
1 Corinthians 15:12 Now if Christ be preached that he rose from the dead, how say some among you that there is no resurrection of the dead?
15:13 But if there be no resurrection of the dead, then is Christ not risen:
15:14 And if Christ be not risen, then is our preaching vain, and your faith is also vain.
15:15 Yea, and we are found false witnesses of God; because we have testified of God that he raised up Christ: whom he raised not up, if so be that the dead rise not.
15:16 For if the dead rise not, then is not Christ raised:
15:17 And if Christ be not raised, your faith is vain; ye are yet in your sins.
Paul was saving the body from the error of the teaching that would deny the resurrection.