"For it is time for judgment to begin with the family of God; and if it begins with us, what will the outcome be for those who do not obey the gospel of God?" NIV translation
Many will be surprised at this verse and try to explain it away but the fact is that even Christians will be judged by God. Everyone on earth will be judged for salvation and that standard is whether your name is found in the Lamb's Book of Life or not. (Revelation 20:11-15) Then, the believers will be judged for rewards and this is a review of what each of us has done with the new life that we received through Jesus Christ. As Jesus said in many parables, those that have been faithful with a little will be given even more.
"And, 'If it is hard for the righteous to be saved, what will become of the ungodly and the sinner?'" NIV translation
Peter seems to be using Proverbs 11:31 here but with a little different wording. Since it took the Son of God dying for the righteous to be saved, what more is available to save the ungodly? This is similar to what it says in Hebrews 6:6 concerning those who turn their back on Jesus Christ. There is nothing left to save them as "they are crucifying the Son of God all over again".
"So then, those who suffer according to God's will should commit themselves to their faithful Creator and continue to do good." NIV translation
When we suffer for following Jesus, we must understand that God is still in control. He is the Creator and therefore has the power to take care of us in any situation. We must commit ourselves to Him and His will for our lives. We can know His will through the Holy Spirit and trust that, if we are in His will, He will take care of us.