God is at work in the hearts of all men and women, not just those who are Christian. Look at the Gospel. True to his intention, Mark was a non-Jew demonstrating what it means to have faith. A very persistent woman who wants her daughter to be healed confronts Jesus. She is so persistent that Jesus gives in to her and fulfills her desire. The most amazing thing is that she is a pagan. How could she possibly know who Jesus is, let alone have faith in him?

The Church in it is theology of conversion and evangelization tells us that even before people hear the Gospel, the Holy Spirit is at work in their hearts preparing them for this very event. The Second Vatican Council also affirms that there are elements of the truth at work in all cultures and religions and that the Church affirms and encourages these aspects of them. St. Paul writes about our ability to know and come to believe in God through the wonder and glory of creation, even without specifically hearing the Gospel proclaimed.

The scriptures tell us that the Lord works with people who are humble and obedient to him and his ways. If we fail to live according to God’s word, his blessings may well pass from us to others, just as Paul explains his proclaiming the Gospel to the Gentiles because the Jews would not listen to him.

If anything, we should be awed by the responsibility we bear as
Catholics. The fullness of the truth necessary for salvation
subsists within the Catholic Church. This means that we have a duty
and a responsibility to live out this truth to the full and, as
such, to be a beacon light lighting up for all peoples the path of
eternal salvation.