"What does the Catholic Church say about our relationship with non-Christian religions?"
Christianity has certainly come a long way, from a small group of followers of Jesus, the Christ, in the first century to more than 2 billion people in the twenty-first century living in every corner of the world! Of all Christians, about half are Catholic. However, there are about 5 billion people in the world who are not Christian. The loves of most of these women and men are shaped and inspired by other religious traditions. In the United States, particularly in the larger cities, we encounter believers of nearly every religious tradition. Because we all share the same neighborhoods, schools, workplaces, as well as the larger world, it is important for Catholics to have the appropriate attitudes towards non-Christian religions.
Since the middle of the twentieth century, Catholics transitioned from an attitude of non-engagement, or very little engagement, of non-Christian traditions to one of respectful dialogue and collaboration. The Second Vatican Council (1962-1965) certainly served as a catalyst for this change of attitude, something that Christians from around the world were asking, particularly in places where Christians constitute a numeric minority (e.g., Asia, Africa). The conciliar document Nostra Aetate, On the Relation of the Church to Non-Christian Religions, is an excellent resource worth reading (you can find this document at www.vatican.va). The document is short and insightful; every Catholic should be familiar with it.
Nostra Aetate invites all Catholics to “recognize, preserve and promote the good things, spiritual and moral, as well as the socio-cultural values” that identify people who are not Christian and seek what is true and holy within the context of their religious traditions (n. 2). Many inspiring efforts to address injustice, bring peace, and build better societies are led by people and organizations from different religious traditions, along with Christians of various denominations, coming together for such common causes. Each draws from the wisdom of their sacred texts and rituals. These different religions invite their adherents, in different ways, to develop a solid spiritual life. As Catholics we acknowledge this calling and thus confirm that God invites every human being to live in holiness. It is part of our Catholic tradition that no one be discriminated against because of their religious convictions.