God was merciful to you, and He certainly wants to use it to change you in some way. Have you asked Him to show you what He is trying to tell you through this accident?
I can only guess, of course, at some possible reasons why He spared you. One reason might be to remind you of the brevity of life, and of your own need of Christ. Perhaps you haven't paid much attention to God so far in life; Christ means little to you, and you have gone through life acting almost as if God didn't exist. Or perhaps you planned to turn to God eventually–but in the meantime you have wanted to live for yourself.
But life is short, and someday your life will be over and you will enter eternity. Without Christ in your heart, however, you won't be ready for that day. The Bible warns, "Salvation is found in no one else, for there is no other name under heaven given to men by which we must be saved" (Acts 4:12). But God loves you, and the most important decision you will ever make is to turn your life over to Christ.
God may also telling you through this accident to treat every day as a gift from His hands–not one to be used selfishly, but to be used for His glory. God has a plan for your life; have you asked Him to show it to you? You will either go through life living for yourself or living for Christ. Commit yourself today to live for Christ and to seek His will for your life.