It is temporary in the sense that the time will at last come when longsuffering will not be needed. Without Love Faith is dead, as are all virtues in Love's absence. This verse is a summary of the whole chapter. The theme is that Love is paramount. Hebrews 11 records the great deeds wrought through Faith, and it was for the Hope of Israel that Paul stood in chains before Agrippa, but he values Love above both Faith and Hope.
Faith requires a promise, some anticipated good, some future benefit.
When this is fulfilled, Faith ends in sight and so is lost. But Love gives all and asks nothing. Love seeks not her own, endures all things, and faileth never. As long as life is present, it cannot perish. It is the foundation and keystone of the Scriptures.