The Apostle sums up his argument on the greatness of Christian love. He shows that every other gift we have received from the Holy Spirit will pass away but love endures forever. The revelatory gifts of the Spirit were given for a specific purpose and passed away when that purpose - the completion of Scripture - was fulfilled. Even the Scriptures do not give us perfect knowledge but we see in them dimly as though looking in a mirror.
The time is coming, though, when we shall not need the Scriptures, because we shall have more perfect knowledge than they can give. We shall not need faith, because we shall have sight. We shall not need hope, because we will have received the object of our hope. But Love will endure forever - nothing shall separate us from the love of God which is in Christ. We are reminded once more what a remarkable thing this is, and exhorted to rejoice in it and praise God for it.