When Satan tries to convince you that you have messed up too bad to be used of God, remind him of John Mark

Brief note on chapters 1-2
    As we read the first couple of chapters of Mark we notice that he is very concise and straight to the point. There is not a lot of added details, just the main points of each incident. We see John the Baptist, Jesus baptism, many miracles and he already starts to tangle with the Pharisees.

A lesson from the Author's life
    Mark was written by John Mark. We met him in the book of Acts and were left with a less than favorable impression as he left Paul and Barnabas on the first missionary journey and later Paul and Barnabas went separate ways as they could not agree on whether to take John Mark with them or not. The point is though that he later became profitable (2 Timothy 4:11, ...Get Mark and bring him with you, for he is useful to me for ministry.), in fact so profitable that God used him to write a portion of scripture. Perhaps you have made some bad decisions in the past that made you or other people think you were not useful in the ministry, but you can redeem yourself and be used of God, if you are willing to do the right things now.