I guess this strikes me a lot, because I see it a lot--the claim by someone to be a believer, a follower of Christ but showing no sign of it in their life. It must all be only mental assent of some sort--or even less, a mere statement. Underneath there is no Spirit, no real commitment to live a transformed life. It is something you say and quickly convince yourself of its veracity . . . then go on acting and being the same unregenerate person you always were. Or, you change for a while, high on a new twist, acting superficially "Christlike" . . . but the game wears off after a time, and though you keep the title "Christian" you fall back into the same old nasty habits: envy, gossip, lying, lustful thoughts, hating. . . .
The sign of a truly changed heart is that love, compassion, patience, encouragement . . . blossom. You are longsuffering with others' failings and mistakes recalling your own. You cease trying to control and constantly harangue others, for you trust that God is in charge and all are His anyhow. So possessiveness increasingly falls away. You clearly know and see your own faults so your are not prone to pointing out and harping on others' failings. Instead, you feel commiserate pity and understanding for all concerned, praising God for all, all along the way.
It's fine if you don't really want to live out what it takes to be an authentic disciple of Jesus. Go with the world, do your thing, fight, compete, put down, lambast, judge unrighteously all you wish. Just don't call yourself a Christian--at least be honest about the situation. . . .