The gospel is "good news," but it is personal good news. Christ did something specific on the cross for the individual. Unless the offer of redemption is personalized, one does not become a child of God.
The Bible describes two kinds of faith or belief. (1) The intellectual brand that truly may know certain facts but those facts are not appropriated to the individual personally. The apostle James writes that the satanic forces of the underworld have this kind of belief. "You believe that God is one. You do well; the demons also believe, and shudder" (James 2:19). (2) Then there is saving faith that appropriates and takes personally the fact of Christ’s sacrifice for one’s personal sins. The writer of Hebrews goes to the heart of the matter:
For indeed we have had good news (the gospel) preached to us, just
as they (the Jews in the wilderness) also; but the word they heard did not
profit them, because it was not united by faith in those who heard. For we
who have believed enter that rest, …" (Heb. 4:2-3)
There is always the temptation to add something to the offer of salvation. Salvation offered by Christ is not cheap. It cost Jesus a terrible death on the cross because of my sins. But all we can do as human beings is trust that sacrifice, the transaction, which has a very personal component to it. God made the good news simple and basic for me personally. I must trust what the Lord did through His Son.
Unfortunately, Roman Catholics believe that Christ died for the Church. There is rarely the statement of personal acceptance of what He did at the cross. Catholics believe they must add good works to His beginning of justification, and even with all the personal efforts in trying to complete salvation, they never really know if they are saved. This is not "good news." The Catholic system plants doubts and fear and adds self-effort in striving to "become" saved by human engineering!
But there are some Protestant groups who do the same. They add to salvation and to the gospel message: good works, water baptism, and sometimes even church membership in their group. This puts the gospel into a framework of exclusivity. You must do this or that to please God or you are not saved!
The rejection of the simple offer of salvation generally can be described as "the evil of an unbelieving heart" (Heb. 3:12). Heart usually implies emotions. But there is more. In other words when one trusts Christ, the emotions are involved (not emotionalism) but also a conscious acceptance of the Lord’s work on the cross. The mind and the soul are responding to what He’s done for us!
That belief for a human being is the major issue (the only issue) for salvation and for becoming a child of God. This is found in so many passages of Scripture. Of course there is John 3:16:
"So thus, definitely loved (Aorist Tense) The God the world, for this reason the Son, the unique born One, [God] gave in order that everyone (pas), the one who is believing into Him, should not himself be destroyed (apolumi, Aorist, Middle, Subjunctive), but (in contrast) should be having (echo, Present, Active, Subjunctive) life eternal."
You cannot squeeze any other requirement into this passage for becoming saved. The verse makes it clear that salvation is (1) by believing, (2) plus nothing else! Belief equals eternal life.
Salvation then is by grace through faith, not through works. "We maintain then a man is justified by faith apart from works of the Law" (Rom. 3:28). And, "Abraham believed God, and it was reckoned to him as righteousness" (4:3; Gen. 15:6).
Do not make the gospel complicated. Do not require more for becoming a child of God than the Lord does. God does not have a check list in heaven to test that one has said everything exactly perfect when coming to Christ for salvation. The Lord understands! However the main concern is that there are those who repudiate some facet of the gospel, making that fact trivial or unnecessary as to what constitutes salvation.
In working with many people who have been born again, I have never seen them deny, malign, or make light of all of the factors we have discussed in these essentials. As new born babes they embraced enthusiastically the essentials that make up the gospel message when those essentials were explained to them.
But be careful of the wolves. There are always those who would destroy the simplicity of the salvation message. May these essentials on what constitutes the gospel be a meaningful and helpful reminder to you of God’s graciousness in the plan of salvation.