Read John 20:30-31

But these are written so that you may continue to believe that Jesus is the Messiah, the Son of God, and that by believing in him you will have life by the power of his name. - John 20:31 (NLT)

God has done many mighty works; some of them are recorded in the Bible, and some of them have occurred in your life. All of them are effective to lead you to faith and then strengthen that faith. The end of the year is an appropriate time to look back and reflect on when and how God has guided and sustained you.