I don't want to come between my friend and his faith?

My very good friend and I care for one another a great deal. His Christian faith is strong and the foundation of his personality. I am Agnostic. I care for him very much, but I don't want to be responsible for his guilt or discontent. He has expressed that he is uneasy with my lack of faith. When I look in his eyes, I see he is distraught. I think I know the anser to this question, but it's too painful to consider. Should I part ways with him, to avoid becoming too attached and having to part later? Should I part with him, as to not contribute to the gap between his actions and his faith?