Biblical repentance (change in thinking about God from unrealistic to realistic) (Acts 20:21) leads to the faith which saves, but it is not salvation.
2 Corinthians 7:10A KJV
[10] For godly sorrow worketh repentance to salvation not to be repented of:
Someone could have the right thinking, right beliefs about God, Jesus, etc., but never get saved. Many who attend church believe and say the right things. They may even be great Bible teachers, but never get saved.
Notice, even the devils got it right.
Matthew 8:28-29 KJV
[28] And when he was come to the other side into the country of the Gergesenes, there met him two possessed with devils, coming out of the tombs, exceeding fierce, so that no man might pass by that way.
[29] And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time?
To be saved, you must not only believe on Jesus as Lord and Christ, but that belief must cause you to receive Him as Lord and Christ.
So what does it mean to receive Jesus as Lord and Christ? It means you believe Jesus’ sacrifice of Himself on the cross paid for all your sins, AND you submit to His authority.
Jesus’ sacrifice.
Ephesians 1:7,13A KJV
[7] In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;
[13] In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed,
Romans 3:24-25 KJV
[24]Being justified freely by his grace through the redemption that is in Christ Jesus:
[25] Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;
Submission.
John 14:21A KJV
[21] He that hath my commandments, and keepeth them, he it is that loveth me:
Romans 6:22 KJV
[22] But now being made free from sin, and become servants to God, ye have your fruit unto holiness, and the end everlasting life.
Romans 14:8A KJV
For whether we live, we live unto the Lord;
Colossians 3:24 KJV
[24] Knowing that of the Lord ye shall receive the reward of the inheritance: for ye serve the Lord Christ.
This is written to Christians. It reveals that they do serve the Lord Christ. Not that they should or might serve Him.