15 And He said to them, “ Go into all the world and preach the gospel to every creature. 16 He who believes and is baptized will be saved; but he who does not believe will be condemned
(Mark 16:15-16 NKJV)
It’s very simple, but good to understand a bit more about baptism.
Water baptism is not only significant to the person being baptized, but it also testifies to his or her community what happened when their life was changed by Jesus. It confirms and strengthens the new believer’s commitment to live a godly life. It also gives the believer the opportunity to openly testify to others of his experience of having been crucified with Christ, buried with Him and raised together with Him to walk in newness of life (Galatians 2:20; Romans 6:4-6).
The significance of water baptism is clear when you understand the meaning of the original Greek verb baptidzo. It means “to immerse.” Immersion is a picture of burial. So, though some churches sprinkle or pour water in the baptismal ceremony, it is when a believer is completely submerged and then raised up out of the water that the significance is more clearly understood. The old man is dead and buried. A new man is raised up out of the grave, reborn to live a new life by the power of the Holy Spirit.
This is important. Without first making Jesus Lord and believing that God raised Him from the dead, water baptism would have no purpose. Water baptism is not the baptism that saves. What cleanses us from sin is not the water but the precious blood that Jesus shed on the cross (see Ephesians 1:7; Hebrews 9:22; Revelation 1:5). If you feel you’ve never properly buried your old, sinful nature and dedicated your whole self to the Lord, don’t wait any longer—find a place to participate in water baptism and get totally free!
This description is quoted from here.