What defines a Christian isn’t just a one-time decision but lifelong delight. God gives us new hearts that treasure Jesus more than anything else.
https://www.desiringgod.org/messages/new-god-new-gospel-new-gladness
https://www.desiringgod.org/messages/new-god-new-gospel-new-gladness/excerpts/the-problem-with-american-christianity