In Nehemiah 8:13-18 God’s people study God’s word.  Their study leads to understanding and their new understanding leads to obedience .  What is the motivation for their obedience? The answer to this question is the eternal difference between religion and gospel.

Whereas religion says, “Obey and then God will love you,” the gospel says, “God loves you, therefore obey.”  Religion produces begrudging obedience trying to win God over, whereas the gospel produces joyful obedience in response to God’s goodness.

Tim Keller identifies numerous differences between religion and gospel:

Religion: Motivation is based on fear and insecurity.
Gospel: Motivation is based on grateful joy.

Religion: I obey in order to get things from God.
Gospel: I obey to get God; to delight in and resemble him.

Religion: When circumstances in my life go wrong, I am angry at God or myself, since I believe that anyone who is good deserves a comfortable life.
Gospel: When circumstances in my life go wrong, I struggle, but I know all my punishment fell on Jesus and that while God may allow this for my training, he will exercise his Fatherly love within my trail.

Religion: My self-view swings between two poles.  If and when I am living up to standards, I feel confident, but them I am prone to be proud and unsympathetic to failing people.  If am and when I am not living up to standards, I feel dispair.
Gospel: My self-view is not based on my moral acheivement.  I am so bad that Jesus had to die for me, and I am so loved that he was glad to die for me.  This leads me to deep humility and confidence at the same time.