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;
Note 1 at 1Co 15:1: Paul had dealt with a number of issues that were reported to him (see Life for Today Study Bible Notes, Introduction to 1 Corinthians) as problems in the Corinthian church. Here, he began to address a doctrinal error that had crept into the church: Some of the Corinthians had quit believing in a bodily resurrection of the dead (1Co 15:12). This chapter makes the most complete treatise on the resurrection of the dead in all of Scripture.
Note 2 at 1Co 15:1: Three things are necessary for people to experience the victorious life that Jesus provided. The Gospel has to be proclaimed (Ro 10:14-17), it has to be received by faith (Eph 2:8 and Heb 11:6), and believers have to continue to stand in the freedom Christ bought for them (Ga 5:1) through faith (Col 2:6-7). All three have to happen. Two out of three will not do.
Note 3 at 1Co 15:1: By comparing 1Pe 5:12 with this verse, we can see that standing in the Gospel is standing in the grace of God. This is another witness that the terms "Gospel" and "grace" are used interchangeably (see note 5 at Ac 20:24).