It depends which version of the Bible you read.
A modern English version is definitely strange, even bolloxing up the "when I was a child" verse quite badly.
King James version has probably the best flow of language and won't feel so awkward, after all, your sister is just saying that love is everything.
Edit: This is a very popular passage from the bible for weddings (but also funerals?!) but is substantially changed from New World Bible type translations as it says charity, not love, so every time the new version says love, the old version says charity - which sounds better in the context of the rest of the words than using love. Charity in this context is not the modern version but is the charity you have for people, situations, rather than the act of giving itself.
Using the old version but substituting "love" for "charity" may be an improvement except at the end: "And now abideth faith, hope, charity, these three; but the greatest of these is charity." These lines we have all heard in one context or another, the new versions use of love instead of charity totally screws that up.
Last edited by AlanQS; 08-23-2010 at 12:33 PM.