To make a donkey lead a cart forward, you need a carrot to reward him if he goes forward and a stick to punish him if he goes backwards. A donkey that leads a cart forward does not do it because he believes it is right, and there is no morality involved in going forward or backward. He does it purely because he wants the carrot and fears the stick. Heaven is a carrot, hell is a stick, and religious people are not more moral than a donkey.
Morality is a bit more involved than sticks and a carrots, forwards or backwards. If it’s true that the “only” motivation is Heaven then you could argue an Atheist doing good is more moral than a Christian, but it’s not true that the only motivation is Heaven. A soldier jumping on a hand grenade doesn’t make that move because he thinks it’s a ticket to heaven, he/she does it to protect something more important.
That is over simplified. Many believers are Christian not because they believe in and fear hell. They choose religion because it makes them feel morally superior to non-believers and also gives them social benefits like fitting into the mainstream and providing community for them and religious education for their kids.
Faithfools believe there is a heaven they goto when they die. Faithfools have the guilt of sin and the fear of hell. So they pray for forgiveness for every little thing they think is a sin.
This is true but "sin" according to Paul was no more than "missing the mark." He used the analogy of an archer shooting at a target. We all "miss the mark' from time to time but you see by this that no one particular thing is a 'sin."
BTW, I am not a fan of Paul and I view him as the biblical antichrist.