Salvation is made necessary because of the unrighteous, sinful condition of all men. Nobody is excluded in their need for redemption from this sinful condition(Romans 3:10). Salvation is not accomplished by anything we do (Titus 3:5, Eph 2:9), but rather is a gift of God given to the individual believer according to His grace (Eph 2:8) if the believers faith is placed in the death, burial, and ressurection of the Lord Jesus Christ as complete payment for sin (1Cor 15:1-4). Christ, fully God and fully man (Col 2:9), who lived a perfect, sinless life while in this world, was made to take the punishment of our sins upon Himself (2Cor 5:21) when He was crucified on the cross at Calvary. By trusting in His finished work, instead of anything that we can do, the believer is baptized (immersed for the sake of identification) by the Holy Spirit (no water necessary) into the One Body of Christ, which is the Church (Eph 4:4-5, 1 Cor 12:13). By the one faith of Eph 4:5, we then share in Christ's baptism into death (by the way, Jesus didn't drown), and are judicially placed on the cross, buried, and raised again a new creature, into newness of life (Romans 6:3-5, 2Cor 5:17),  by which means we recieve the imputed righeousness of Christ (Romans 4:24).