I instantly recognized the piano playing as yours (I guess it helps that I knew it was a track from you though).
But yeah, I like all the instruments and the progression. Both the deep and the higher piano notes are beautiful. The ukulele fits in nicely too.
But I have to agree with johnfn that though the song is beautiful, the mixing might need some work for it to be one with the intruments. I don't know exactly how to do it though, so the best I can advise, is listen to johnfn's advice XD
Overall though, I think the song is beautiful in it's current state as well. It's great to hear some more singing of this kind on Newgrounds nowadays.
P.S. Oh, and I almost forgot! In case it wasn't clear from my earlier review, I found some melodical similarities between "For Love is strong as Death" and "Return", which first sparked the idea that the first mentioned hinted at the latter. Some examples of such parts would be 4:19-4:22 and 5:17-5:20 of "FLisaD", and 1:17-1:20 and 4:58-5:00 of "Return".
There are lots of other short spots as well. I know they're pretty short, and far from identical, but they were similar enough that together with the themes and atmosphere, I though it was intentional, hehhe :)
Thanks for the long response!
And whoah. You are in two competitions at the same time now o.O
I hope you'll be able to put aside some time to compose tracks we'd all like to listen to, you yourself included ;)