I have an elderly acquaintance of about eighty, who has lived a life of unbroken selfishness and self-admiration from the earliest years, and is, more or less, I regret to say, one of the happiest men I know.  From the moral point of view it is very difficult! As you perhaps know, I haven't always been a Christian.  I didn't go to religion to make me happy.  I always knew a bottle of Port would do that.  If you want a religion to make you feel really comfortable, I certainly don't recommend Christianity.