A dualism, as I'm thinking of it here, is a simplistic way of looking at the world in terms of good and evil, "darkness" and "light". It is not denying the two ways set forth in Scripture: the broad way that leads to destruction, the narrow way that leads to life. Nor that there are those who have faith in God through Christ, and those who do not. Nor is this denying the existence of good and evil, light and darkness.
The dualism I speak of here fails to see the complexity of what our world is. Of what we see. Of what we experience. As we can embrace the fact that there is much we do not understand, and there is much goodness in the same places where we can find evil (and look in the mirror, too), then we can more and more appreciate the good that is there, yet not be at all surprised to see the evil present.
I'll take one general example. If one studies the United Nations they will find that through that organization much good is occurring in the world. At the same time they will find scandals, surely double standards, inconsistencies, and failure. But that does not deny all the good it does in the world.
Failing to see God's work and handiwork all over, even a fallen world and a creation under his curse, is to miss an important aspect of the Story we are all a part of. And it fails to see the good that God can redeem in a society. What if Joseph would have taken a dualistic approach when he was sold to Egypt? He could have been pious. In a corner. By himself. Rejecting all Egypt had to offer. Instead, we see what God accomplished through him, even as he became a leader there. Same is true of Daniel. And I believe the same is true of us, as one holy nation, scattered throughout the earth.
I can enjoy and appreciate a contribution from someone who does not share my faith in Jesus. Would I like to see them come to share in my faith? Of course. And we can pray and love to that end. But we can't simply push them aside as an "other". Jesus calls us to be a "neighbor" to all.
What dualism might shape your view of the world and of others? Is it Scriptural? Why or why not?