Latin/Latine From the Abbey of Solesmes' Liber Cantualis	English/Anglica (A loose translation of mine -- the reader can find another, somewhat more exact translation, based on a slightly different chorus, at Thesaurus Precum Latinarum)
1. Ubi caritas est vera, Deus ibi est. Congregavit nos in unum Christi amor. Exsultemus, et in ipso iucundemur. Timeamus, et amemus Deum vivum. Et ex corde diligamus nos sincero.	1. Wherever we find true charity, God is there. Christ's love has gathered us into one: let us rejoice, and take delight in him; let us fear, and let us love the living God; And with a sincere heart let us commit to him.
2. Ubi caritas est vera, Deus ibi est. Simul ergo cum in unum congregamur: Ne nos mente dividamur, caveamus. Cessent iurgia maligna, cessent lites. Et in medio nostri sit Christus Deus.	2. Wherever we find true charity, God is there. So let us gather as one: yet beware, lest our minds be divided: may our malicious quarrels cease, may we end our disputes, that Christ our God may remain in our midst.
3. Ubi caritas est vera, Deus ibi est. Simul quoque cum beatis videamus, Glorianter vultum tuum, Christe Deus: Gaudium quod est immensum, atque probum, Saecula per infinita saeculorum.	3. Wherever we find true charity, God is there. May we, along with the blessed, see your glorious face, O Christ our God: joy that is boundless and good, through all the infinite ages.

It is not easy to translate Ecclesiastical Latin's sense of caritas with just one word; it means "spiritual love", or "love in action", the love which is born from a profound respect of the other (or the Other). (Note that I have linked to a classical Latin dictionary, not an ecclesiastical Latin dicionary.) Another word for love is amor, which is more along the lines of the affectionate love humans express (indeed one version of this hymn uses the chorus ubi caritas et amor...) The name of the Catholic Church's charitable arm is Caritas; and we obtain the English word charity from caritas.

I had trouble choosing a translation of dilig- as well; I chose "commit" after pondering the Lewis & Short dictionary entry at the Perseus Digital Library.