"This  second  epistle, beloved, I now write  unto  you;  in [both]  which  I stir up your pure minds by way  of  remembrance: That  ye may be mindful of the words which were spoken before  by the  holy prophets, and of the commandment of us the apostles  of the  Lord and Saviour: Knowing this first, that there shall  come in  the  last days scoffers, walking after their own  lusts,  And saying, Where is the promise of his coming? for since the fathers fell  asleep, all things continue as [they were] from the  beginning  of the creation. For this they willingly are  ignorant  of, that  by the word of God the heavens were of old, and  the  earth standing  out  of the water and in the water: Whereby  the  world that  then  was, being overflowed with water, perished:  
"But  the heavens and the earth, which are now, by the  same word  are  kept in store, reserved unto fire against the  day  of judgment  and  perdition  of ungodly men. But,  beloved,  be  not ignorant of this one thing, that one day [is] with the Lord as  a thousand years, and a thousand years as one day. The Lord is  not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
"But the day of the Lord will come as a thief in the  night; in the which the heavens shall pass away with a great noise,  and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up." (2 Peter 3:1-10)
Remember  that the passing away of this earth is  not  until after the thousand year millennium has passed. Note too that  the world perished once before in Noah's day.

"..  the  ark was a preparing, wherein few, that  is,  eight souls  were  saved  by water. 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) We cannot have a good  conscience without the acceptance of His sacrifice for  our sins.  He did it all. We had nothing to do with it. We  could  be perfect every day and not get saved. Jesus did it all. He is  the only  one who could have paid the price where God was  concerned. The  payment  had to be perfect and God is the only  one  who  is perfect. Jesus is God in the flesh. He purchased our eternal life with Himself to make sure that nothing could go wrong. Our salvation  is certain, guaranteed, certified, insured, assured,  sure, held  in  trust,  on deposit, pledged, warranted,  sponsored  by Christ Jesus and endorsed.
Noah just believed God's preposterous story to start  building an ark on dry land. There was no water in sight anywhere. God told  him how to build it and what all needed to be  placed  into the ark and Noah believed it and built it to specs. The  ridicule Noah  received  from  the people around him  was  outlandish.  It didn't make sense to the people around him and did not even  have a  positive effect on the people around him. While Noah  followed the  Lord's prompting to get on with the ark, the people kept  on with their lives as usual. Like a thief in the night suddenly the water  came  rushing from wells, from  heaven,  from  everywhere. There was no other warning but Noah's relentless building  toward God, believing His message rather than the world's.
The  "baptism  doth also now save" should be  understood  in light  of verse 1 Peter 3:20 "eight should were saved by  water." Noah  and his family, being in the ark, were able to pass  safely "through"  the waters (seen in the Greek word dia [1223]. In  the same  way, the term "baptism" (verse 21) should be understood  as the visible representation of deliverance through Christ, just as the  ark  represented deliverance from the waters of  the  Flood. When  a person accepts Christ, he is saved; when the believer  is baptized,  he  is identified with the One who has  delivered  him (i.e., Jesus Christ). (KJV Hebrew Greek Key Study Bible p.1540)
Jesus  said:  "He that believeth and is  baptized  shall  be saved;  but he that believeth not shall be damned." (Mark  16:16) How  can  we be made responsible for an infant baptism  when  our parents decided to get us saved. It doesn't work as you can  see. We  are expected to get baptized when we understand what  we  are doing and make the decision for ourselves.
The  word "believeth" is pisteusas (from pisteuo [4100],  an aorist participle referring to one who has believed at some  time in  the past. Also, baptistheis (907), translated "is  baptized", is  an  aorist  participle but in the passive  voice.  This  form refers  to  an act of outward obedience, in this  case,  baptism. Therefore, the correct translation here should be stated, "He who believed and who was baptized shall be saved." However, the  Lord adds,  "...but he that believeth not shall be damned." It  should be  noted that this negative statement does not include a  reference  to  baptism, making it clear that what saves  a  person  is living  faith  in Jesus Christ. This is made clear  in  Ephesians 2:8,  "For by grace are saved through faith.. " The word  "saved" is translated from the Greek word sesosmenoi, which is a  perfect passive  participle. It means that this salvation took  place  at some point in the past and is continuing on in the present, being accomplished by Jesus Christ Himself.
If  baptism were necessary for salvation, Ephesians 2:8  and many  other  verses  should have been translated  "ye  are  saved through  faith  and  baptism." There are examples in  the  NT  of people who were baptized for selfish reason, rather than for  the purpose  of  demonstrating their inner, saving  faith  in  Christ (Luke  3:7-9,  the Pharisees; Acts 8:9-25, Simon). Baptism  is  a distinct act of obedience apart from salvation. This is clarified by the order in which the words "believe" and "baptize" occur  in the  text  (cf. Matt. 28:19 [note here that the  word  "teaching" precedes  the  mentioning of "baptism"];  Acts  2:38;  10:44-48). (ibid., pp. 1259, 1260)
Looking  at Noah once again. He believed God which  is  when the  grace  of  God occurred. Had Noah not  followed  through  in building the ark he would have drowned like the rest of them.  It would  have  proven that he didn't really believe  that  God  was real. Noone who truly believes would dismiss what God has to  say because  God  is offering an ark to each one of us which  can  be reached  by  co-operating with God. Jesus taught us how  to  take advantage  of  the ark which represents safety here  and  forever after.
"The  Lord is not slack concerning his promise, as some  men count  slackness;  but is longsuffering to us-ward,  not  willing that  any should perish, but that all should come to  repentance. (2 Peter 3:9) Does that mean, like some have us believe, that all men  are going to be saved eventually? No! What it means is  that the  door  is open to all human beings, rich or  poor,  black  or white  and  Jew or Gentile. Why aren't all saved?  Because  Jesus saith  unto him, "I am the way, the truth, and the life:  no  man cometh  unto the Father, but by me. (John 14:6) He purchased  us. He paid the price, not Buddha, not Mohammed, not the Virgin Mary, not Joseph Smith Jr., or any other god.
In the following verse God teaches us that "goodness of God" makes  us realize how gracious He is and only a fool  would  turn such goodness down. Repentance is coming to see our ignorance and lost  condition  without Him and grabbing unto his  coattail  for mercy and forgiveness which He has for us in abundance. By  turning  Him  down "..despisest thou the riches of his  goodness  and forbearance  and longsuffering; not knowing that the goodness  of God  leadeth thee to repentance?" (Romans 2:4) It leadeth to  God "Who  will have all men to be saved, and to come unto the  knowledge of the truth." (1 Timothy 2:4)