In its bare simplicity God’s plan of salvation is to take earthly men and women, who are made in his image, and make them his heavenly children and heirs in Christ (Rom. 8:14-17,29f.;1 Cor. 15:47-49; Eph. 1:4-6; Tit. 3:7; Heb. 2:10) so that they might live eternally to the praise of his glory (Eph. 1:12; Rev. 4 & 5, cf. Ps. 30:9; 115:17f.; Isa. 38:18-20; 43:7,21. For OT “salvation”, see e.g. Ex. 6:6-8; Lev. 22:32f.; 25:38,55; 26:12f.,45; Dt. 4:20, 9:29. Note how “servants” in the OT become “sons” or “children” in the NT).
The Corruptibility of Creation
The Bible teaches that man, though created in the image of God, emanates from the earth and is hence flesh. Since the earth has a beginning in time (Gen. 1:1), it is clearly temporal and inevitably has an end (Heb. 7:3; 1:10-12). It follows from this that all created things, including fleshly man, are mortal or corruptible by nature and in direct contrast to God himself who is eternal (Rom. 1:23; 8:19-25, cf. Gen. 8:22; Ps. 78:39; 90:2; 102:25-27; 103:14-16; Isa. 40:6-8; 51:6,8; 54:10; Mt. 5:18; 24:35, etc.). Thus Paul concludes that flesh and blood as opposed to spirit cannot inherit the kingdom of God (1 Cor. 15:50, cf. John 3:5f. Note how in Gal. 4:29f. the son of the flesh is cast out like a slave in contrast with the true spiritual son in John 8:35 and Hebrews 3:6).
The Commandment Promising Life
Since he is made in the image of God, man is intended to be like God and so to seek immortality and incorruptibility (Rom. 2:7,10; 1 Pet. 1:7). If he exercises his proper dominion he will be crowned with glory and honour (Gen. 1:26,28; Ps. 8:5f.; Rom. 2:10). With eternal life in view, God gave Adam a commandment. It warned of death but implicitly promised (eternal) life on the condition that it was kept (Gen. 2:17, cf. Lev. 18:5; Dt. 30:15-20; 32:46f.; Mt. 19:17; Lu. 10:28; Rom. 7:10; 10:5, etc.). Through the weakness of the flesh (Gen. 3:6, cf. Rom. 7:14; 8:3) Adam, the man of dust (1 Cor. 15:47), was unable to fulfil the condition, and, like him, by divine design so are all his children (Rom. 11:32; Gal. 3:22) with the single exception of Jesus, the second Adam (Rom. 3:23; 5:12; 8:3; Heb. 2:17; 4:15; 1 Pet. 2:22).
The Second Adam
Since men and women who are ‘flesh’ could not and cannot perfectly keep the commandments (Gen. 3:6; Job 4:17-19; 15:14; 25:4; Eccl. 7:20; Rom. 3:19f.; 1 Cor. 1:29; Gal. 2:16; 3:10f.), God, with the intention of being himself the sole Saviour of his people (Isa. 43:3,11; 45:21-23; 59:16; 63:5; Rom. 11:32; Gal. 3:22), has devised another means of bringing them into his heavenly presence (1 Pet. 3:18). He has sent his Son, the virgin-born man of heaven (1 Cor. 15:47), to serve as the second Adam, to fulfil the law in the flesh (Rom. 8:3; Gal. 4:4f.; Heb. 2:10ff.), to bring life and immortality (Gk. incorruption) to light through the gospel (2 Tim. 1:10) and thus to conquer the last enemy death (1 Cor. 15:26; Heb. 2:14f.). As both God and man it is Jesus who alone achieves dominion (Heb. 2:9; John 16:33; 17:4f.; Rom. 8:3; Rev. 5:5,12f.) and by so doing represents and saves all those who put their trust in him (Heb. 2:10-18).
The Eternal Plan’s Heavenly Consummation
According to Paul, God’s plan is eternal: it was formed in eternity and extends to eternity (Rom. 8:29f.; Eph. 1:4,9; 2 Tim. 1:9; Tit. 1:2, cf. 1 Pet. 1:20). Thus, in the course of time, having received a heavenly call (Phil. 3:14; 1 Thes. 2:12; Heb. 3:1; 1 Pet. 5:10) through the preaching of the word of Christ (Rom. 10:17; 1 Cor. 1:9; 2 Thes. 2:14), we accept the promise of eternal life (Tit. 1:2; 1 John 2:25) and are justified (accounted righteous) by faith in Christ (Rom. 1:16f.; 3:22; 5:1). Then, born again (James 1:18, cf. John 3:6) and led by the Spirit, we are conformed to (Rom. 8:29; 2 Cor. 3:18) and perfected in the image of Christ (cf. Phil. 3:12-14; Heb. 6:1; 9:14; 10:22) who is himself the image of God (Heb. 1:3).
Finally, at death when we have finished our course in the time set by the Father (cf. Gal. 4:2), we receive complete salvation from our sin and bondage to the corruption of creation (Rom. 8:19-25; Gal. 1:4). Thus, since our flesh, like the material creation itself, cannot inherit the kingdom of God (1 Cor. 15:50), both are removed (Heb. 12:27; Rev. 20:11; 21:1) and destroyed (2 Cor. 4:16-5:5; 2 Pet. 3:7,10-12). However, our bodies as such are redeemed (Rom. 8:23) and replaced as spiritual or heavenly bodies like that of Christ (Phil. 3:21) so that we may share eternally in the life and glory of God (Rom. 5:2; 8:18; 1 Cor. 15:42-57; 2 Cor. 5:17; 1 Pet. 5:10, etc.) as his children and heirs (Luke 20:36; Rom. 8:14-17; 1 John 3:1-3). This “eternal weight of glory” (2 Cor. 4:17, cf. Rom. 8:18,24f.) is variously described as the crown of life (Jas. 1:12; Rev. 2:10, cf. 3:11), the crown of glory (1 Pet. 5:4), the crown of righteousness (2 Tim. 4:8) which is doubtless eternal life in heaven (1 Pet. 1:4, cf. 1 Cor. 9:24), the inheritance of all those who finish their earthly race or pilgrimage looking to Jesus the pioneer and perfecter of their faith (Heb. 12:2).
At this point God’s original promise of eternal life implied in Genesis 1:26,28 (cf. Ps. 8:5; Heb. 2:9f.) and 2:17 is fulfilled. As those who have received the unfading crown of glory through Christ (1 Pet. 1:4; 5:4), we shall worship at the throne of God and the Lamb, see his face and reign forever and ever (John 17:24; Rev. 22:3-5, cf. 3:21).
John Wesley on Salvation
“I want to know one thing, the way to heaven…. God himself has condescended to teach the way…. He hath written it down in a book. O give me that book: At any price give me the book of God! I have it: here is knowledge enough for me. Let me be Homo unius libri * …. I sit down alone: only God is here. In his presence I open, I read His book; for this end, to find the way to heaven.”
* A man of one book.