John Henry Newman on Interreligious Issues

It may be objected, that, if the feeling of a good conscience be evidence to us of our justification, then are persons in a justified state who are external to the Church, provided they have this feeling. I reply briefly,--for to say much here would be out of place,--that everyone will be judged according to his light and his privileges; and any man who has really the testimony of a good conscience is acting up to his light, whatever that is. . . It but shows that he is accepted in that state in which he is, be it one of greater favour or less, heathenism, schism, superstision, or heresy; and that, because his faults and errors at present are not wilful.

John Henry Newman, Plain and Parochial Sermons Volume V, "Sermon 17: The Testimony of Conscience."