AUGUSTINE:
They could see the head, but they could not yet see the body. We can see the body, but we believe about the head. They are two: husband and wife, head and body, Christ and the church. He showed himself to the disciples and promised them the church. He showed us the church and ordered us to believe about himself. The apostles saw one thing, but they did not see the other. We also see one thing and do not see the other. Having the head there with them, they believed about the body. Having the body here with us, we should believe about the head.