8 Love never ends; as for prophecies, they will pass away; as for tongues, they will cease; as for knowledge, it will pass away. 9 For our knowledge is imperfect and our prophecy is imperfect; 10 but when the perfect comes, the imperfect will pass away. 11 When I was a child, I spoke like a child, I thought like a child, I reasoned like a child; when I became a man, I gave up childish ways. 12 For now we see in a mirror dimly, but then face to face. Now I know in part; then I shall understand fully, even as I have been fully understood. 13 So faith, hope, love abide, these three; but the greatest of these is love. (RSV)
Cessationists often believe that the meaning of “that which is perfect” is the NT. Thus, prophecies and speaking tongues are no longer valid because we have the New Testament (see e.g., this blog). The perfect which Paul awaits however cannot be the NT since Paul had no idea that there would be collection of books used in the post-apostolic church called the NT. This is anachronistic exegesis. Furthermore, it is not correct to say that it is a good theological understanding of the passage, since the NT itself does not have a theology of the NT–i.e., it has obviously a theology or theologies, which we call NT theology, but it does not discuss the NT as a theological category. The biblical theology purported by cessationists is actually coherent only from a post-reformation point of view.
That which is perfect for Paul is properly understood to be the second coming of Christ who we will know directly and face to face. The NT is not perfect in the sense of the Greek term, teleion (complete) ; it partially reveals to us the object of our faith, Jesus Christ. When Jesus Christ is come, then we will see face to face the author and perfecter of our faith. Until then, we are still in need of the gifts of the Spirit to guide us.