Baptism is a religious sacrament marked by the symbolic immersion of the whole body into water and resulting in the admission of the recipient into the community of Christians.
It symbolizes the washing away of sins after repentance and embracing the doctrines of Christianity following the teachings of Jesus Christ as the only mediator interceding between man and God the father.
Mt 3:11 I indeed baptize you with water to repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Spirit, and with fire:
Jn 4:1 When therefore the Lord knew that the Pharisees had heard that Jesus made and baptized more disciples than John,
Jn 4:2 (Though Jesus himself baptized not, but his disciples,)
The biggest manifestation of baptism happened at the time of Noah. The people being corrupted, God sent a great flow of waters over the earth, for the destruction from under the heaven of all flesh in which is the breath of life; everything on the earth had come to an end.
1 Pet 3:20 Who formerly were disobedient, when once the long-suffering of God waited in the days of Noah, while the ark was preparing, in which few, that is, eight souls, were saved by water.
Though eight souls were saved by water, there is still no guarantee that they and their offspring will no longer commit sins.
Eccles 7:20 For there is not a just man upon earth, that doeth good, and sinneth not.
But what is this baptism that Jesus is referring to? It is but by making us free from the sense of sin before God, through the coming again of Jesus Christ from the dead.
Mk 10:38 But Jesus said to them, Ye know not what ye ask: can ye drink of the cup that I drink of? and be baptized with the baptism that I am baptized with?
Mk 10:39 And they said to him, We can. And Jesus said to them, Ye shall indeed drink of the cup that I drink of: and with the baptism that I am baptized with shalt ye be baptized;
After baptism which is the putting away of the filth of the flesh, living with a good conscience is a must until we die and then later, like Jesus Christ, be resurrected on the day of judgment.
1 Pet 3:21 The like figure to which, even baptism, doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience towards God,) by the resurrection of Jesus Christ:
Heb 13:18 Pray for us: for we trust we have a good conscience, in all things willing to live honestly.