The gospel is the death, burial, and resurrection of Jesus Christ, who was God manifest in the flesh.
Once Saved ALWAYS Saved
Titus 1:2
“In hope of eternal life, which God, that cannot lie, promised before the world began;”
John Chapter 3:15-18
15 That whosoever believeth in him should not perish, but have eternal life.
16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
John 3:36
“He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.”