Why does 1 Peter 3 use the flood as an analogy of baptism, and in what sense does baptism save us now?

This text is from a letter written by David Gooding in 1999.

The key verse here is 1 Peter 3:20: 'were saved through water'. The first important thing to notice is that the verb in Greek is not the simple verb sōzō, but the compound verb diasōzō. It means to 'preserve' someone or something 'through some danger or dangerous situation'. See Acts 23:24: 'to bring him safe unto Felix'.

In the passive, it means to 'come safe through'. See Acts 27:44: 'they came through [the waves] safe to land. See also Acts 28:1, 4.

In 1 Peter 3:20, the ark was the means in which a few came safely through water. The water did not save them: the ark saved them. Water and a watery death is what they had to be saved from, by being brought through it. Without the ark they never would have got through the water. The water was sent as God's judgment on the world.

Baptism is a symbolic burial and resurrection. The water of baptism is a symbol of death and burial—from which we are raised and thus saved. The water does not save us: it is the symbol of the judgment of God. In Christ we died under the judgment of God; but in Christ we have passed through that judgment and have been raised from the dead.