Being single or "in relationship" is a concept that the Spirit uses as a teaching aid. The key to relationships is forgiveness and this is the only purpose of relationships as taught in ACIM. The use of romantic relationships can be a great speed-up for the mind to recognize its relationship with God.
We seem to have a variety of relationships. Yet we are teaching and learning about ourselves in every interaction. We want to tune into guidance and relationships are part of the plan. We want to forgive as deeply as we can in every encounter. Building commitment . . .