In this Borderland of thought and perception, the closest meeting we can have with the Truth is to see that thought cannot "know" it, and that we can forgive ourselves for this shortcoming. We live in a world of "separation," and this is why yogis for millenniums have given attention to "joining" with the Truth.
What we need to "do" for this to happen is to see that thought is a limitation imposed on our being, and perception always falls short of Knowledge. We can get close to the door to Heaven in this "borderland" of thought, and sit at the Altar to Truth, just outside of Heaven's Gate, but to enter into Heaven we would have to leave all perception behind. (Therefore the body as well).
We are not asked to do this now, as students of ACIM. We are asked, though, to perceive a "forgiven world" in which we bring our thought to silence. This is our work to do. This is the "decision for Heaven" that will move our minds closer to this final absorption into the Heavenly State of Being. Meanwhile, "Forgiveness is our function as the Light of the world."