Why be moral if there is no punishment in the afterlife?  Daren Jaques, of Just Atheists, answers the question like this:

Well, there are lots of reasons. 1) I will not be as successful in life if others cannot trust me, and if all I ever do is look after myself, then people will not trust me. This applies to lying, stealing, and harming others generally. 2) I do not believe that I can be “absolved” of my wrongdoing through either a shaman’s magic (confession) nor through the ritual drinking of human/god blood (communion). That means I need to try and be as good and kind as possible every time I act because there are no do-overs. (source)

Daren is right that he will not be as successful in life as he could be since no one around him will have any reason to trust him if he is very self-serving.  But he is also correct in saying that confession and ritual drinking of blood will not absolve him of his sins.  There are no do-overs–you get a choice one time in life, and it is best to do the moral thing then and there.  You will never get another chance.

Daren says that it is not the threat of eternal punishment that motivates him to do good deeds, it is the mutual benefit of all.  There are two problems with this statement.  First, Daren has admitted that an objective good and evil exist, which is part of the theist worldview, not the atheist.  The atheist view does not allow for such things to exist–things can only be what they are.

Second, in his preceding statement, Daren lists success and winning trust as his primary motivation, not altruism.  Daren wishes to be successful in this life and win the praise of others.  Jesus points this out in Matthew 6:1-18 that this is the mark of a hypocrite.  Daren isn’t being moral for the sake of being moral.  He’s doing it for the sake of being noticed positively by other people.

Daren states that the theist is only moral to avoid eternal punishment.  Nothing could be further from the truth.  Only the Christian, committed to Christ, is truly free to will and do good for its own sake.  Those not in Christ may do good, but it is always for their own ends.  In his attempt to prove otherwise, Daren has proven the truth of that statement.