After referring to the deliverance experienced by the eight humans in the ark, the Christian apostle Peter wrote:

“That which corresponds to this is also now saving you, namely, baptism, (not the putting away of the filth of the flesh, but the request made to God for a good conscience,) through the resurrection of Jesus Christ.

1 Peter 3:21,

20. What shows that water baptism alone is not enough for one to gain everlasting life?

²⁰ It is not water baptism alone that results in salvation. While water can wash away filth or dirt, it is “not the putting away of the filth of the flesh” by a solemn external washing that saves. Note that Peter said that salvation is “through the resurrection of Jesus Christ.” Hence, the individual who is baptized needs to acknowledge that everlasting life is only possible because the Son of God died a sacrificial death, was resurrected on the third day and finally was exalted to the right hand of God.​—Romans 10:9, 10.

21. How does a person get a “good conscience”?

²¹ Furthermore, the apostle Peter put the emphasis on a “request made to God for a good conscience.” To come into possession of such a good conscience, all who wish to get baptized first need to repent of their past wrongdoing, exercise faith in God’s provision for everlasting life, turn around from a bad course and dedicate or commit themselves fully to the doing of the divine will. Baptism is the public symbol of this inward resolve. After following through on what Jehovah God now requires, the baptized disciple comes into possession of a good conscience. As long as he maintains that good conscience he is in a saved condition. God’s adverse judgment will not be expressed against him.​—Compare Acts 2:38-40; 3:19; 10:34-48.