flameoffire
Phenomenal hymn.
The writer meant:
"If I had all the world (were the whole realm of nature mine), it wouldn't be enough of an offering to be worthy of You (that were an offering far too small). Your amazing, divine love deserves everything I have to give (Love so amazing, so divine demands my soul, my life, my all).
That's my understanding and paraphrase. I hope that helps.