The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ: (1 Peter 3:21)
Baptism is a testimony or an outward expression or sign or as in this passage, “the answer” of that “good conscience toward God.” A candidate for baptism is examined and asked concerning his spiritual condition, to which he should be able to claim a true and living relationship with God by faith in Christ alone, a repentance of sin, and attest to the genuine regenerating work of the Holy Spirit in his heart, prior to baptism. Once again, in the Bible, a person is saved before they participate in the ordinance of baptism.
“The like figure” refer to the waters of baptism and the waters of Noah’s flood. Water was instrumental in delivering Noah and his family from God’s judgment. Noah was already saved prior to entering the ark. His faith moved him to build the ark. But he and his family could only be delivered from the great flood, if they would enter into the ark. A Christian is first, saved by faith alone. Before he enters the baptismal waters, he already has been saved by the glorious cross-work of the Lord Jesus Christ. The Christian’s baptism delivers him from God’s judgment (not in the salvific sense) but in a physical sense (similar to Noah). In Peter’s day, Christians were persecuted for their faith in Christ. It wasn’t easy to take a public stand (Baptism). No doubt there were Christians who internally had true saving faith, but not wanting to declare publicly their faith in Christ hence, a conflict of conscience arises. Besides, God chastises every child he receives (Heb. 12:6) and so if a Christian knows he is supposed to be baptized, but doesn’t, he will have to endure God’s chastening hand. In Baptism, the Christian is taking a public stand for Christ, and is in effect saying, “I am in Christ, and because of that I am no longer a part of this anti-God world system.” His baptism is a witness to God's deliverance.
The onus of this passage is on the resurrection of the Lord Jesus. Whatever we may believe about Baptism, or anything else, our entire system of religion is vain had it not been for the resurrection of the Lord. Our hope is founded upon the fact that Christ is risen, and that same resurrection power is what grants unto us eternal life (Eph. 1:15-23) and not any external religious act.