"3 Know this first of all, that in the last days mockers will come with their mocking, following after their own lusts, 4 and saying, “Where is the promise of His coming? For ever since the fathers fell asleep, all things continue just as they were from the beginning of creation.” 5 For when they maintain this, it escapes their notice that by the word of God the heavens existed long ago and the earth was formed out of water and by water, 6 through which the world at that time was destroyed by being flooded with water. 7 But by His word the present heavens and earth are being reserved for fire, kept for the day of judgment and destruction of ungodly people.
8 But do not let this one fact escape your notice, beloved, that with the Lord one day is like a thousand years, and a thousand years like one day. 9 The Lord is not slow about His promise, as some count slowness, but is patient toward you, not willing for any to perish, but for all to come to repentance."
The content of these verses is something all Christians can relate to, that since the crucifixion Christians have awaited the return of Christ. Though Jesus tells us in Mark 13:32 that only God the Father is aware of the day and hour of Christ's return, many people have made predictions of the exact day and hour repeatedly through the centuries, leading many to doubt that it will even happen.
Peter explains in the second paragraph that God's time runs much slower than earthy time, and that because of this we really have no idea how Christ and God count time. Our time is based on planetary movement around the sun, and of the movement of the moon around the earth, things which are irrelevant to the heavenly beings. Verse nine is especially important when we understand that the true nature of Salvation from Christ is Christ giving us guidance in our lives to turn away from sin, repent of our wrong-doing, and develop new habits of thought and behavior that don't separate us from Him and God. This takes time, and as Peter says, God is not "willing for any to perish" but wants to give everyone time to come to Salvation, repent, and take up their cross to follow Christ.
If you want to accept Salvation from Christ here are some resources:
A Prayer for Salvation from Christ:
Lord Jesus, I confess my sins and ask for your forgiveness. Please come into my heart as my Lord and Savior. Take complete control of my life and help me to walk in Your footsteps daily by the power of the Holy Spirit. Thank you Lord for saving me and for answering my prayer.
A more detailed step by step process:
https://www.wikihow.com/Accept-Jesus-Into-Your-Life