A Course in Miracles:
Who has need for sin? Only the lonely and alone, who see their brothers different from themselves. It is this difference, seen but not real, that makes the need for sin, not real but seen, seem justified. And all this would be real if sin were so. For an unholy relationship is based on differences, where each one thinks the other has what he has not. They come together, each to complete himself and rob the other. They stay until they think that there is nothing left to steal, and then move on. And so they wander through a world of strangers, unlike themselves, living with their bodies perhaps under a common roof that shelters neither; in the same room and yet a world apart.
A holy relationship starts from a different premise. Each one has looked within and seen no lack. Accepting his completion, he would extend it by joining with another, whole as himself. He sees no difference between these selves, for differences are only of the body. Therefore, he looks on nothing he would take. He denies not his own reality because it is the truth. Just under Heaven does he stand, but close enough not to return to earth. For this relationship has Heaven's Holiness. How far from home can a relationship so like to Heaven be? (T22.in.2)
There is a difference between an unholy relationship and a holy relationship. The holy relationship has God, truth and holiness as its goal, the unholy relationship the ego, the illusion, and unholiness or sin. In a holy relationship you come to find your Self. In an unholy relationship you come to deny your Self. This reading adds to the discussion the idea that in a holy relationship the goal is to learn of your sameness, in the unholy relationship your differences. An agreement in a holy relationship would sound like: “I want to get home to God, I want to remember my oneness with God and you. I would like to support you in getting home to God. Would you like to do the same for me?” In an unholy relationship, no matter how “loving” you think it is, the agreement is: “I want to use you to project all my guilt onto and to act out all my past vengeance. You don’t really exist so try not to intrude on my fantasy. If you do, I will just trade you for another more willing projectee.”
Now, in order to enter into a relationship where your goal is to get that you are the same, the supernatural sinless Son of God, you have to have previously accepted that goal for yourself. In order to reclaim your Identity you must give up your identity. Remember, what makes you an individual in the ego’s thought system is differences. Are you willing to “give up” all your differences so you can heal the sick and raise the dead and live in the joy and Peace of God?
The ego argues that that would be death. And its right. That would be its death but it would also be your homecoming.
A holy relationship, however newly born, must value holiness above all else. In an unholy relationship, each one is valued because he seems to justify the other's sin. Each sees within the other what impels him to sin against his will. And thus he lays his sins upon the other, and is attracted to him to perpetuate his sins. And so it must become impossible for each to see himself as causing sin by his desire to have sin real. Yet reason sees a holy relationship as what it is; a common state of mind, where both give errors gladly to correction, that both may happily be healed as one. (T22.III.9)