Your last sentence strikes at the heart of it.
I’m not Lutheran and Martin Luther had ample faults - as we all do. But I remembered something I read once, searched for it, and found it posted. I think it is very relevant for this thread - and a warning to many mega-churches. Although it IS longer than some people are supposed to be able to focus:
In regard to doctrine we observe especially this defect that, while some preach about the faith by which we are to be justified, it is still not clearly enough explained how one shall attain to this faith, and almost all omit one aspect of the Christian faith without which no one can understand what faith is or means. For Christ says in the last chapter of Luke that we are to preach in his name repentance and forgiveness of sins.
Many now talk only about the forgiveness of sins and say little or nothing about repentance. There neither is forgiveness of sins without repentance nor can forgiveness of sins be understood without repentance. It follows that if we preach the forgiveness of sins without repentance that the people imagine that they have already obtained the forgiveness of sins, becoming thereby secure and without compunction of conscience. This would be a greater error and sin than all the errors hitherto prevailing. Surely we need to be concerned lest, as Christ says in Matt. 12:45 the last state becomes worse than the first...
...We are to teach the people diligently that this faith cannot exist without earnest and true contrition and fear of God, as it is written in Psalm 110 and Prov. 1, “The fear of the Lord is the beginning of knowledge.” And Isaiah says in the last chapter: “On whom does God look except on the trembling and contrite heart?”...
...For many who hear that they should believe, so that all their sins will be forgiven, fashion their own faith and think they are pure. Thus they become secure and arrogant. Such carnal security is worse than all the errors hitherto prevailing....
-Luther’s Works; Volume 40; Church and Ministry II
http://afellowtruthseeker.blogspot.com/2014/07/martin-luther-on-sanctification-and.html
Worth repeating for emphasis:
“It follows that if we preach the forgiveness of sins without repentance that the people imagine that they have already obtained the forgiveness of sins, becoming thereby secure and without compunction of conscience.”