Not the removal of dirt from the body but the pledge of a clear conscience toward God

1 Peter 3:18-22

For Christ also suffered once for sins, the righteous for the unrighteous, to bring you to God. He was put to death in the body but made alive in the Spirit. After being made alive, he went and made proclamation to the imprisoned spirits— to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built. In it only a few people, eight in all, were saved through water, and this water symbolizes baptism that now saves you also—not the removal of dirt from the body but the pledge of a clear conscience toward God. It saves you by the resurrection of Jesus Christ, who has gone into heaven and is at God’s right hand—with angels, authorities and powers in submission to him.

Why?

Jesus suffered once for sins, the righteous for the unrighteous, to bring us to God. This is the salvation for all of us. In Noah's time, most people did not trust in God's word, now through the blood of Jesus Christ everyone can made alive in the Spirit. This salvation is easy to get but most men still trust in themselves.

Jesus was put to death in the body but made alive in the Spirit. This Spirit is imprisoned spirit.

The water in Noah and only eight people were saved, so same as this generation only a few turn to Jesus and be saved. This water symbolizes baptism. 

We are not only through water baptism but also Spiritual baptism.

removal of dirt from our body, more important is the pledge of a clear conscience toward God.

How?

Pursue a clear conscience toward God! May I be a blessing to others and know the Lord.