Baptism is about cleansing the conscience rather than cleansing the body of earthly dirt.
1 Peter 3:8-22 8 Finally, all of you, have unity of spirit, sympathy, love of the brethren, a tender heart and a humble mind. 9 Do not return evil for evil or reviling for reviling; but on the contrary bless, for to this you have been called, that you may obtain a blessing. 10 For "He that would love life and see good days, let him keep his tongue from evil and his lips from speaking guile; 11 let him turn away from evil and do right; let him seek peace and pursue it. 12 For the eyes of the Lord are upon the righteous, and his ears are open to their prayer. But the face of the Lord is against those that do evil." 13 Now who is there to harm you if you are zealous for what is right? 14 But even if you do suffer for righteousness' sake, you will be blessed. Have no fear of them, nor be troubled, 15 but in your hearts reverence Christ as Lord. Always be prepared to make a defense to any one who calls you to account for the hope that is in you, yet do it with gentleness and reverence; 16 and keep your conscience clear, so that, when you are abused, those who revile your good behavior in Christ may be put to shame. 17 For it is better to suffer for doing right, if that should be God's will, than for doing wrong. 18 For Christ also died for sins once for all, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit; 19 in which he went and preached to the spirits in prison, 20 who formerly did not obey, when God's patience waited in the days of Noah, during the building of the ark, in which a few, that is, eight persons, were saved through water. 21 Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a clear conscience, through the resurrection of Jesus Christ, 22 who has gone into heaven and is at the right hand of God, with angels, authorities, and powers subject to him.
