My God I love thee

There is a hymn that begins "My God I love thee not because" which has always been something of a source of amusement, because so far as the words themselves go, you can't exactly tell, by the end of the first line, whether you are about to explain to God what exactly is the reason why you don't love him, or what exactly is not the reason why you love him. Indeed the text remains unclear about which is your intention, even when you've added that it is because you hope for heaven thereby—obviously we all know that it would be odd to not love him because that way you hope to get to heaven, so we can make sense of the hymn by bringing our own knowledge to the interpretation. But the words themselves, in the translation we are accustomed to, do not manage to get the sense clear.

There is nothing to choose between the NEH and the EH as regards authenticity of the words of this hymn. Both give the same words and attribute them to Edward Caswall (1506-1552), as a translation of a Latin original beginning "O Deus ego amo te".

1. O Deus, ego amo te,
   Nec amo te, ut salves me,
   Aut, quia non amantes te
   Æterno punis igne.
2. Tu, tu, mi Jesu, totum me
   Amplexus es in cruce;
   Tuliste clavos, lanceam,
   Multamque ignominiam,
3. Innumeros dolores,
   Sudores, et angores,
   Et mortem, et hæc propter me,
   Ac pro me peccatore.
4. Cur igitur non amem te,
   O Jesu amantissime,
   Non, ut in cœlo salves me,
   Aut ne æternum damnes me,
5. Nec præmii ullius spe;
   Sed sicut tu amasti me?
   Sic amo et amabo te,
   Solum quia Rex meus es,
   Et solum, quia Deus es.

Notice that the Latin has the advantage of indicating that the singer declares that he/she does love God, and does not add "not because" in the first line. In English, because "God" and "I" and "love" are monosyllabic in English, you can't complete the line in the same metre by just saying "O God I love thee".

My interest in this hymn is two fold. First it has an interesting history: the Latin is not the original but is a translation of a Spanish original beginning "No me mueve, mi Dios, para quererte" (and notice that this line does exactly what the English version does, and starts by saying that I am not moved to love God...)

The author of the Spanish original is not known, but is thought to be St Francis Xavier, who is also credited with the Latin translation, though it seems very doubtful that the Latin is actually by him. Several Latin versions are known (see the account in the Catholic Encyclopedia) starting with one  by Joannes Nadasi in his "Pretiosæ occupationes morientium" (Rome, 1657) which follows the Spanish by beginning "Non me movet, Domine, ad amandum te". The one that begins "O Deus ego amo te" is of unknown authorship and appeared in "Cœleste Palmetum" (Cologne, 1696).

What about Caswall's English translation? I am unsure what the last line of the first verse should be. EH and NEH both make us sing "are lost eternally". This is all very well (a nicely delicate way of describing the fate of those who don't love God) but the rhyme between "eternally in line 4, and "thereby" in line two is not great.

Oremus Hymnal agrees with EH and co. The Nethymnal (aka Cyberhymnal) gives "may eternally die" which rhymes with "thereby" but doesn't scan. This seems implausible.

The Catholic Cornucopia (along with a few other sources I've checked) gives "must burn eternally" which appears to be closer to the Latin, and plausibly what Caswall wrote, though it still suffers from the half rhyme. I can imagine that some editors thought "lost" was a more comfortable phrasing for modern sensibilities. My guess would be that Caswall wrote that, and that it's been altered due to the fashions of theological squeamishness, because we don't much dwell these days on the hell fires that are supposed to torment those who are "lost eternally".