Sherem correctly observes that the gospel is the doctrine of Christ. It is the “glad tidings, ... that he came into the world, even Jesus, to be crucified for the world, and to bear the sins of the world, and to sanctify the world, and to cleanse it from all unrighteousness; that through him all might be saved whom the Father had put into his power and made by him” (D&C 76:40-42).
The gospel is the good news of what the Lord Jesus has done for us, things which we could not do for ourselves. To enjoy the full benefits of Christ’s atoning act, men must exercise faith in him, repent of their sins through him, be baptized unto him, receive the Holy Ghost from him, and endure in faith unto the end (see 3 Nephi 27:13-21).
“Verily, verily, I say unto you,” the Savior said in our day, “he that receiveth my gospel receiveth me; and he that receiveth not my gospel receiveth not me. And this is my gospel-repentance and baptism by water, and then cometh the baptism of fire and the Holy Ghost, even the Comforter, which showeth all things, and teacheth the peaceable things of the kingdom.” (D&C 39:5-6; cf. 2 Nephi 31:2; 2 Nephi 32:6.)