Dom Gueranger on Baptism of Desire
From The Liturgical Year by Dom Gueranger for Thursday in Whitsun week: Even those whom Providence has permitted to be born of heretical-parents-if they have lived in the disposition of mind of entering the true Church as soon as they should find it, and have faithfully corresponded, by a virtuous life, to the grace given them through the merits of the Redeemer-they, too, are children of the Church. 
Michael Fighting
