Here's a lesson from the Discipleship Course I have led over the years that is about the questions you've asked:
Discipleship Lesson 2: The Gospel of Salvation
I. Salvation: Entering into relationship with God.
Why must one be saved?
1 John 1:5
5 This is the message which we have heard from Him and declare to you, that God is light and in Him is no darkness at all.
Psalms 5:4
4 For You are not a God who takes pleasure in wickedness, Nor shall evil dwell with You.
Romans 3:23
23 for all have sinned and fall short of the glory of God,
Isaiah 59:2
2 But your iniquities have separated you from your God; And your sins have hidden His face from you, so that He will not hear.
John 3:19
19 And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil.
Psalms 1:5-6
5 Therefore the ungodly shall not stand in the judgment, Nor sinners in the congregation of the righteous.
6 For the Lord knows the way of the righteous, But the way of the ungodly shall perish.
Ezekiel 18:4
4 "Behold, all souls are Mine; The soul of the father as well as the soul of the son is Mine; The soul who sins shall die.
Romans 6:23
23 For the wages of sin is death...
How is one saved?
II. Repentance: Changing one’s mind.
Matthew 4:17
17 From that time Jesus began to preach and to say, "Repent, for the kingdom of heaven is at hand."
Mark 1:14-15
14 Now after John was put in prison, Jesus came to Galilee, preaching the gospel of the kingdom of God,
15 and saying, "The time is fulfilled, and the kingdom of God is at hand. Repent, and believe in the gospel."
Luke 5:31-32
31 Jesus answered and said to them, "Those who are well have no need of a physician, but those who are sick.
32 I have not come to call the righteous, but sinners, to repentance."
Acts 3:19
19 Repent therefore and be converted, that your sins may be blotted out...
Acts 3:26
26 To you first, God, having raised up His Servant Jesus, sent Him to bless you, in turning away every one of you from your iniquities."
Repentance is, at its heart,
a change of mind, an alteration or amendment of one’s thinking. Is repentance always and only
from sin in the Bible? No. In the Old Testament, God “repents” more than anyone else; but He does not, of course, repent from sin. Repentance, then, is not a turning away
from sin. Repentance is
the change in one’s thinking that
gives rise to a turning away from sin
. It is only as one hears the truths of the Gospel, recognizes one’s sinfulness, rebellion toward God, and need of a Saviour, and reorients one’s thinking in conformity to what one has heard – repents – that salvation is possible. This is why we see in the verses above that repentance is distinguished from and
precedes believing the Gospel, conversion, and remission of sins. (Please read
Addendum 3: Repentance)
III. Belief:
Romans 10:9-13
9 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved.
10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation.
11 For the Scripture says, "Whoever believes on Him will not be put to shame."
12 For there is no distinction between Jew and Greek, for the same Lord over all is rich to all who call upon Him.
13 For "whoever calls on the name of the Lord shall be saved."
John 3:3-7
3 Jesus answered and said to him, "Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God."
4 Nicodemus said to Him, "How can a man be born when he is old? Can he enter a second time into his mother's womb and be born?"
5 Jesus answered, "Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God.
6 That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.
7 Do not marvel that I said to you, 'You must be born again.'
John 3:16-18
16 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.
17 For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
18He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God.
John 3:36
36 He who believes in the Son has everlasting life; and he who does not believe the Son shall not see life, but the wrath of God abides on him."
Ephesians 2:8-9
8 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God,
9 not of works, lest anyone should boast.
IV. Confession of sin: Agreeing with God about your sin.
1 John 1:9
9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
James 4:8-10
8 Draw near to God and He will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double-minded.
9 Lament and mourn and weep! Let your laughter be turned to mourning and your joy to gloom.
10 Humble yourselves in the sight of the Lord, and He will lift you up.
Proverbs 28:13
13 He who covers his sins will not prosper, but whoever confesses and forsakes them will have mercy.
Matthew 3:5-6
5 Then Jerusalem, all Judea, and all the region around the Jordan went out to him
6 and were baptized by him in the Jordan, confessing their sins.
From what is one saved?
Romans 6:22-23
22 But now having been set free from sin, and having become slaves of God, you have your fruit to holiness, and the end, everlasting life.
23 For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.
Romans 5:8-9
8 But God demonstrates His own love toward us, in that while we were still sinners, Christ died for us.
9 Much more then, having now been justified by His blood, we shall be saved from wrath through Him.
Colossians 1:13-14
13 He has delivered us from the power of darkness and conveyed us into the kingdom of the Son of His love,
14 in whom we have redemption through His blood, the forgiveness of sins.
Galatians 1:3-5
3 Grace to you and peace from God the Father and our Lord Jesus Christ,
4 who gave Himself for our sins, that He might deliver us from this present evil age, according to the will of our God and Father,
5 to whom be glory forever and ever. Amen.
Romans 8:2-4
2 For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death.
3 For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh,
4 that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit.
Romans 6:6-11
6 knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin.
7 For he who has died has been freed from sin.
8 Now if we died with Christ, we believe that we shall also live with Him,
9 knowing that Christ, having been raised from the dead, dies no more. Death no longer has dominion over Him.
10 For the death that He died, He died to sin once for all; but the life that He lives, He lives to God.
11 Likewise you also, reckon yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord.
Galatians 3:13-14
13 Christ has redeemed us from the curse of the law, having become a curse for us (for it is written, "Cursed is everyone who hangs on a tree"),
14 that the blessing of Abraham might come upon the Gentiles in Christ Jesus, that we might receive the promise of the Spirit through faith.
To what is one saved?
John 4:13-14
13 Jesus answered and said to her, "Whoever drinks of this water will thirst again,
14 but whoever drinks of the water that I shall give him will never thirst. But the water that I shall give him will become in him a fountain of water springing up into everlasting life."
John 5:24
24 "Most assuredly, I say to you, he who hears My word and believes in Him who sent Me has everlasting life, and shall not come into judgment, but has passed from death into life.
Galatians 5:13
13 For you, brethren, have been called to liberty; only do not use liberty as an opportunity for the flesh, but through love serve one another.
Romans 5:1-2
1 Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ,
2 through whom also we have access by faith into this grace in which we stand, and rejoice in hope of the glory of God.
Colossians 1:21-22
21 And you, who once were alienated and enemies in your mind by wicked works, yet now He has reconciled
22 in the body of His flesh through death, to present you holy, and blameless, and above reproach in His sight--