Decisions, doctrine, and deeds don’t define faith. Most fundamentally, Christianity is cherishing, treasuring, and delighting in all that God is for us in Jesus.
https://www.desiringgod.org/messages/new-god-new-gospel-new-gladness/
https://www.desiringgod.org/messages/new-god-new-gospel-new-gladness/excerpts/what-makes-a-christian