How is love greater than faith? 1 Corinthians 13:13 (NIV)   
  
  13 And now these three remain: faith, hope and love. But the greatest of these is love.


Sola-fide states that faith alone brings salvation. In this oft-quoted verse, Paul is clearly saying that love is greater than faith. 

How can any attribute be greater than that which is necessary for salvation?
According to Christ, the greatest command is to "love the Lord your God with all you heart, soul, mind, and strength" and the second like is to "love your neighbor as yourself".

Also according to Christ, He is "the way, the truth, and the life" - NO one comes to the Father except through Him.

Paul expands on Jesus' statements through his writings - never in contradiction of our Lord, but always in congruence with Him. 

By telling the Corinthians that "the greatest of these is love", he has not excluded faith and hope. Rather, he has pointed the way higher than "mere" faith. Higher than "mere" hope. Paul is telling the Corinthians that faith and hope are only the beginning of the journey - the culmination is in completely fulfilling Christ's own command to "love one another".