The rose you speak about knows. There are no doubts on her part. That's why she can "just" be. You can also say that because the rose "just" is, she knows beyond any doubt. When you are/know there is neither hope nor despair. It seems to me that you equate knowing with intellectual understanding.

Anyway. Is such pure existence selfish? You can call it that way -- it's a pinnacle of selfishness as there's no separation. Is it nihilistic? Absolutely no. But it's sort of tautological -- the meaning of life turns out to be life.

Furthermore, and contrary to what you say, it's the end of religion. But, as you also say and I agree, it truly "opens a world of grace, nonjudgement, compassion, and gratitude." I would go even as far as to say that genuine love is not possible before.