"you first loved us so that we might love you—not because you needed our love, but because we could not be what you created us to be, except by loving you."

     William of Saint Thierry, On the contemplation of God 9-11, as quoted in Liturgy of the hours, vol. 1, p. 271 (Office of readings for the Third Monday of Advent).  Latin as reproduced at http://www.almudi.org/portals/0/docs/breviario/fuentes/breviario.html (but cf. against SC 61, 90-96):

Et sic plane, sic est: amásti nos prior, ut amarémus te; non quod egéres amári a nobis, sed quia id, ad quod nos fecísti, esse non poterámus, nisi amándo te.