One with the Lord, the believer is eternally secure. There is nothing they can do to lose or forfeit their place because those who believe in the Son of God have been given eternal life (see entry for John 3:15).
Eternal means forever and everlasting. The eternal gospel (Rev. 14:6) declares that the blood of Jesus obtained an eternal redemption (Heb. 9:12) giving us an eternal salvation (Heb. 5:9). In him you have an eternal inheritance (Heb. 9:15), guaranteed by an eternal covenant (Heb. 13:20), resulting in eternal life (John 3:16) and a welcome into the eternal kingdom (2 Pet. 1:11) by the eternal God (Rom 16:26). This good news should bring you eternal comfort (2 Thess. 2:16).
Yet many Christians aren’t comforted. They are anxious and insecure because they have heard mixed-up messages that suggest they can lose their salvation. If only they trusted the promises of God. For a Christian to lose their salvation and be expelled from the kingdom:
God would have to forsake us, when he said he wouldn’t (Heb. 13:5)
God would have to cast us out, when he said he wouldn’t (John 6:37)
God would have to condemn us, when he said he wouldn’t (Rom. 8:1)
God would have to withdraw his Spirit, when he said he wouldn’t (John 14:17)
God would have to remember our sins, when he said he wouldn’t (Heb. 10:17)
God would have to forget that we are his children, when he said he wouldn’t (Is. 49:15)
God would have to blot our names out of the book of life, when he said he wouldn’t (Rev. 3:5)
And that’s just a taste.
There are more than 130 scriptures in the New Testament guaranteeing the eternal security of the believer. These promises assure the believer that:
you belong to God (1 Pet. 2:9) and no one can snatch you his hand (see entry for John 10:29)
you are kept safe to the end by Jesus (see entry for 1 Cor. 1:8-9)
God’s grace is greater than your failings (see entry for Rom. 5:20)
God is not holding your sins against you (see entry for 2 Cor. 5:19)
Jesus intercedes for you (see entry for Rom. 8:34)
salvation is an irrevocable gift from God (Rom. 11:29)
you are a citizen of heaven (Php. 3:20)
you have been made new and the old has gone (see entry for 2 Cor. 5:17)
God will never abandon his children (see entry for John 8:35)
There is nothing partial or half-baked about what Christ accomplished. Those who draw near to God are saved forever (Heb. 7:25). We may make and break our promises to God, but our salvation is based on his unbreakable promises to us. “Does he promise and not fulfill?” (Num. 23:19)
Saint, you are one with the Lord, and his future is your future. Since Jesus isn’t going to lose his salvation, it can’t happen to you. Truly “God has saved us” (2 Tim. 1:9).