St. Paul informs the Jewish Christians in his letter to the Hebrews that as we run the race to heaven, there is this large group of people that have run the race already.  They have been perfected and await our arrival.  They are Saints, "Holy Ones," who are cheering us on to not give up. 

Their gifts and their talents have been perfected in heaven and God is pleased to use their prayers to help us in our struggles like taking our cars to a machanic whose gifts far exceed our own to repair a busted engine.  We have the gift of their friendship and they want to help us get to heaven.  This is what the Creed means when we say we believe in the Communion of Saints.