God’s patience with sinners is extraordinary.  While Noah was building the ark on God’s instruction over a period of many years, in dry land with no sea in sight, many came to mock the boat builder and its Designer (2 Peter 3:3-6).  But their refusal to believe the good news that the ark would save people from the flood, eventually swept them to their death (Matthew 24:39) and to hell (2 Peter 2:4-5).  God’s patience with wicked people is designed to lead them to repentance (Romans 2:4).  Peter affirms this, “The Lord is not slow in keeping his promise, as some understand slowness. Instead he is patient with you, not wanting anyone to perish, but everyone to come to repentance.” (2 Peter 3:9).

Noah is an example of faithful obedience to God; and those who ridiculed him are examples of foolish people whose physical death is followed by eternal condemnation.  Peter wants his readers to be like Noah who despised the ridicule and mockery, as Jesus did, and did not lose heart (Hebrews 12:2-3).  Today’s verses have had a variety of interpretations, including the idea that the physical act of baptising with water has saving power.  But other Bible verses do not agree because we are saved through God's grace alone when we put our faith in Jesus the Saviour (Ephesians 2:8-9).  We are forgiven when we repent (Acts 2:38), and baptism should confirm repentance and resurrection life.  Religious leaders who came to John the Baptist were refused baptism because there was no evidence of genuine repentance (Matthew 3:7-8).
 
God longs to save all who obediently find their refuge in Jesus; like Noah's family who were kept safe in the ark as recorded in Genesis 7-9.  The flood was a 'baptism' which engulfed them; and yet their faithful obedience and God's grace preserved them.  But the flood also separated them from the wicked world that had despised God's provision.  After that 'baptism' there was no going back to the old world - it had gone.  So today, water baptism marks out the person who has declared faith in Christ, having repented of sin; and it affirms the beginning of a new life, which renounces the old life.
 
All that is most reassuring to the conscience.  A bad conscience can see no hope, but a good conscience breeds confidence in God's promise of a good future with Him.  We can be confident that as Jesus was raised from the dead by the power of the Spirit, so it is possible to live a resurrection life now (Romans 6:4): and to receive a resurrection body like that of Jesus when He comes again.  God wants you to have a quiet conscience that gives you real confidence to live His new life today, and to refuse to go back to old ways.