The person who is most in danger of failing in the Christian life is the one who thinks he's strong enough to live it on his own.
Why is this? The reason is because he doesn't think he needs God's help to live the way he should. But that isn't true! We're all weak, and not one of us has the ability in our self to live the way God wants us to live. The Apostle Paul was the greatest Christian who ever lived, and yet he knew failure -- when he relied on himself. He wrote, "I know that nothing good lives in me.... For I have the desire to do what is good, but I cannot carry it out" (Romans 7:18).
But listen: God knows our weakness -- and when we come to Christ, God comes to live within us by His Holy Spirit. One reason He does this is so we can turn to Him for the help we need. You don't have the strength to live the way God wants you to live -- but God wants to give that strength to you, and He is only a prayer away. The Bible says, "The Spirit helps us in our weakness" (Romans 8:26).
Don't let your fear of failure -- or anything else -- keep you from Christ. God loves you, and even when you fail (and you will), He stands ready to forgive you and strengthen you. Turn to Christ and open your heart and life to Him today.