With all due respect I have to disagree. I can’t tell you how many people have “been on fire for God” in their youth...claiming to believe and be saved, only to slide into complacency and even disbelief later in life
There is no contradiction here. The rules naturally are followed if love is the foundation and motivation, and thus the examples you invoke simply have not kept their first love.
“....thus the examples you invoke simply have not kept their first love.”
But is the experience of “first love” by which we tell many Christians that you have “eternal peace” (in the sense of a known-security of one’s salvation). Are you saying that the loss of this love has no impact on their salvation?
Hence the root difference between David and Saul's misadventures.
The "I should be able to get away with x" or "Here is why I should get away with y" crowd uses God's grace as if it were an EBT card. The type of entitled folks who use the cards to buy filet mignon and expensive organic snacks, having zero thought, respect or regard for the ones who are actually paying the bill.
The parasitic class will be shocked, confused, and outraged when their cards go dead. *Especially* when card of the young mother (who is grateful for the sustenance after being abandoned by her husband), continues to work just fine.
Spiritual concepts really do sit right out in the open and manifest plainly. Somewhere along the way, the spirit of the law became conflated with the letter of the law, so when some people see "Law" they have a strong, negative visceral reaction. Mindfulness (thoughtful observance and respect) became a "work", thus "not necessary" for salvation.
The word "Christ" is not a nebulous doctrinal concept, just as the phrase "son of David" is not a mere genealogical detail. Without interacting with him personally (physically), people have the volume of documentation in the text of all who he is and how he does things.
Moses described him (e.g. Deu 6:5-9), and David also, and many others. People either believe God's word (written evidence), or not.
Matthew 12:41 The men of Nineveh shall rise in judgment with this generation, and shall condemn it: because they repented at the preaching of Jonas; and, behold, a greater than Jonas is here.