Jesus Christ became the author of eternal salvation unto all them that obey Him  (Hebrews 5:9). The apostle Paul wrote to the Romans,  But God be thanked that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you. Being then made free from sin, ye became the servants of righteousness  (Romans 6:17-18).

Peter posed the question ...What shall the end be of them that obey not the gospel of God?   (I Peter 4:17). The apostle Paul answers, ...the Lord Jesus shall be revealed from heaven with His mighty angels, In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ   (2 Thessalonians 1:7-8).

Paul wrote the Romans, ...Being then made free from sin, ye became the servants of righteousness   (Romans 6:18).

...We also should walk in newness of life   (Romans 6:4).

 ...The Lord knoweth them that are His. And, Let every one that nameth the name of Christ depart from iniquity   (2 Timothy 2:19). For the grace of God that bringeth salvation hath appeared to all men, Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world; Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ; Who gave Himself for us, that He might redeem us from all iniquity, and purify unto Himself a peculiar (or special, His own possession) people, zealous of good works.   (Titus 2:11-14).

 So then faith cometh by hearing, and hearing by the word of God   (Romans 10:17).

How then shall they believe in Him of whom they have not heard?   (Romans 10:14).

 It is written in the prophets, AND THEY SHALL BE ALL TAUGHT OF GOD. Every man therefore that hath heard, and hath learned of the Father, cometh unto Me   (John 6:45). Who hath ears to hear, let him hear   (Matthew 13:9). It pleased God by the foolishness of preaching to save them that believe   (I Corinthians 1:21).

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  (John 3:36).

 ...Without faith it is impossible to please Him: for he that cometh to God must believe that He is, and that He is a rewarder of them that diligently seek Him  (Hebrews 11:6).

He that believeth and is baptized shall be saved; but he that believeth not shall be damned   (Mark 16:16).

 ...He that believeth not is condemned already...   (John 3:18).

 I tell you, Nay: but except ye repent, ye shall all likewise perish   (Luke 13:3).

Godly sorrow worketh repentance to salvation...  (2 Corinthians 7:10).

Repent ye therefore, and be converted, that your sins may be blotted out...   (Acts 3:19).

Repent , and be baptized everyone of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost   (Acts 2:38).

Repentance is a change of mind toward sin which results in a change of conduct. [NOTE: Holy Ghost in the King James Version is translated Holy Spirit in most other versions or translations].

Whosoever therefore shall confess Me before men, him will I confess also before My Father which is in heaven   (Matthew 10:32).

That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised Him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness: and with the mouth confession is made unto salvation   (Romans 10:9-10).

I believe that Jesus Christ is the Son of God   is the Bible confession (Acts 8:37).

Jesus said, Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost   (Matthew 28:19).

Repent, and be baptized everyone of you in the name of Jesus Christ for the remission of sins...   (Acts 2:38).

...And he commanded them to be baptized in the name of the Lord  (Acts 10:48).

They that gladly received his word were baptized...   (Acts 2:41).

Know ye not, that so many of us as were baptized into Jesus Christ were baptized into His death? Therefore we are buried with Him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life  (Romans 6:3-4).

And now why tarriest thou? Arise, and be baptized, and wash away thy sins, calling on the name of the Lord   (Acts 22:16).

For ye are all the children of God by faith in Christ Jesus. For as many of you as have been baptized into Christ have put on Christ   (Galatians 3:26-27).

Know ye not, that so many of us as were baptized into Jesus Christ, were baptized into His death   (Romans 6:3).

In whom we have redemption through His blood, even the forgiveness of sins   (Colossians 1:14).

And this is the record, that God hath given to us eternal life, and this life is in His Son   (I John 5:11).

The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ: Who is gone into heaven, and is on the right hand of God; angels and authorities and powers being made subject unto Him   (I Peter 3:21-22).

baptized into Jesus Christ, ...baptized into His death, ...buried with Him by baptism, and like as Christ was raised from the dead...even so we also should walk in newness of life   (Romans 6:3-4), they were then told in verse 17 that they had obeyed from the heart that form of doctrine which was delivered them.   What form of doctrine   had they obeyed? For the answer read: I Corinthians 15:1 thru 4.