I think it is as simple as just "believing in Christ". Repentance and regeneration follow real faith. The fallen angels "know" who Jesus Christ is, but they don't believe in Him unconditionally.
I think there are many who are saved but who torture themselves unnecessarily by denying the saving power of Christ, believing they must “add” to His sacrifice because they worship an insufficient Savior who just can’t get the job done.
Then they don't believe in Him unconditionally. Therefore they have added to The Gospel and in turn believe a different gospel.
“I think it is as simple as just “believing in Christ”. Repentance and regeneration follow real faith. The fallen angels “know” who Jesus Christ is, but they don’t believe in Him unconditionally.”
Agreed on the last sentence, which, if you read my posts is what Boatbums and I discussed and why I chose to break that phrase down into a definition. As for repentance and regeneration, they do not FOLLOW saving faith but happen at the same time and are an integral part of saving faith. One cannot know Christ unless one is regenerated; and repentance is necessary for salvation as well.