The gospel of your salvation

Intro

The gospel of salvation from the lake of fire is summed up in Romans 1:1 - Romans 5:5. The gospel is defined in 1 Corinthian 15:3-4.

Scripture

Salvation

Eternal security

(John 16:13 [KJV]) Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.

(Ephesians 2:8-9 [KJV])
 [8] For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
 [9] Not of works, lest any man should boast.

(John 6:47 [KJV]) Verily, verily, I say unto you, He that believeth on me hath everlasting life.

(John 3:16 [KJV]) 
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.

(Romans 11:29 [KJV]) For the gifts and calling of God are without repentance.

(II Corinthians 1:22 [KJV]) Who hath also sealed us, and given the earnest of the Spirit in our hearts.

(John 5:24 [KJV]) Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.

(Romans 8:38-39 [KJV])
 [38] For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come,
 [39] Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.

(II Timothy 1:12 [KJV]) For the which cause I also suffer these things: nevertheless I am not ashamed: for I know whom I have believed, and am persuaded that he is able to keep that which I have committed unto him against that day.

(I John 5:13 [KJV]) These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.

(John 5:24-25 [KJV])
 [24] Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.
 [25] Verily, verily, I say unto you, The hour is coming, and now is, when the dead shall hear the voice of the Son of God: and they that hear shall live.

(Ephesians 1:13-14 [KJV])
 [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, ye were sealed with that holy Spirit of promise,
 [14] Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.

(John 3:18 [KJV]) 
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.

(Romans 10:16 [KJV]) But they have not all obeyed the gospel. For Esaias saith, Lord, who hath believed our report?

(Jonah 3:10 [KJV]) 
And God saw their works, that they turned from their evil way; and God repented of the evil, that he had said that he would do unto them; and he did it not.

Jonah 3:10 is relevant in order to show that God considers it a work to repent of your sins and eternal salvation is not of works, least anyone should boast (Ephesians 2:9). So you don't have to repent of your sins to be eternally saved.

How to preach the gospel

You should preach the gospel without expecting anything in return.

(Luke 17:6-10 [KJV])
 [6] And the Lord said, If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it should obey you.
 [7] But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat?
 [8] And will not rather say unto him, Make ready wherewith I may sup, and gird thyself, and serve me, till I have eaten and drunken; and afterward thou shalt eat and drink?
 [9] Doth he thank that servant because he did the things that were commanded him? I trow not.
 [10] So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.

not grudgingly or of necessity.

(II Corinthians 9:7 [KJV]) Every man according as he purposeth in his heart, so let him give; not grudgingly, or of necessity: for God loveth a cheerful giver.

but willingly.

(I Corinthians 9:17 [KJV]) For if I do this thing willingly, I have a reward: but if against my will, a dispensation of the gospel is committed unto me.