Nobody can predict who is saved. A devout Muslim who sincerely believes they have found God may well be saved, but it would be through the power of Jesus who opened up the door to heaven for mankind. So accepting Jesus as your saviour is still the best option.
A good god would save everybody though. Your thinking is confused and contradictory.
Yes, reading some of the literature on salvation and grace is like reading a complicated conveyancing document, there are so many ifs and buts, and riders. You can't earn it, but according to Alan, you can keep trying, God loves a tryer, except our own efforts are supposed to count for nothing. And so on and so on. It reminds me of the old rules in a boarding house, no visitors allowed, no smoking in rooms, no noise, no thinking, etc. And God might reply to you, but if he doesn't, never mind.