Religion says, if I obey, God will love me.
Gospel says, because God loves me, I can obey.
Religion has good people & bad people.
Gospel has only repentant and unrepentant people.
Religion values a birth family.
Gospel values a new birth.
Religion depends on what I do.
Gospel depends on what Jesus has done.
That approach is a good way to help people understand the difference between two apparent similar entities (at least to the outsider). One of the most important problems that teachers face is creating an understanding in their students of the distinctions between two sides of an argument or how two positions or entities differ from one another. This type of presentation goes a long way in solving that problem, where the more common narrative approach (common in sermons or other monologues) usually fails to adequately cement the differences in the hearers (or in this case, readers).
With that in mind I thought I would try and add a little to the list Mark Driscoll started.
Christian Religion says, in the end it depends on me.
Christian Gospel says, it always depends on God.
Christian Religion allows for a certain amount of ambiguity about Jesus.
Christian Gospel only has people who are for or against Jesus Christ. The lukewarm and ambiguous are unambiguously vomit.
Christian Religion has good people who feel sure about their salvation because they are, after all, good.
Christian Gospel has redeemed people who are working out their salvation with fear and trembling.
Christian Religion has a if you do this, God will do that economy.
Christian Gospel has a God does what God wants because he is God economy.
Christian Religion has a power structure.
Christian Gospel has a servant structure.
Christian Religion continually builds ever more complex structures.
Christian Gospel continually reduces life to simple choices.
Christian Religion has high regard for celebrity and the cult of personality when deciding who God has called.
Christian Gospel has high regard for humility and the belief that anyone can be used by God at any time for anything.
Christian Religion is a rigid organizational ladder everyone who aspires to serve God must climb.
Christian Gospel sees no one between God and the service he calls a person to. The Church only agrees with God.
Christian Religion immerses itself in the political structure, seeking influence to facilitate change.
Christian Gospel is apolitical, relying instead on redeemed men to act redemptively.
I am sure you can come up with some of your own examples. Go ahead and try. It is a good exercise for clarifying your understanding of the gospel.
Grace and peace to your day.