To really know God is to commit yourself to Him — to let Him work in your life and the lives of others around you, and to tie yourself to His eternal Word.
You will be an effective witness for Christ if you are aware of living out God’s will for you. Daily recommit yourself to Jesus as Lord. Find out what the Bible says about decisions you make.
If you’re troubled with doubts, and I suppose everyone is at sometime or other in his or her life, get into God’s Word, and read the promises that He’s made and the prophecies that have been fulfilled.