The pastor was probably reading from the 13th chapter of the book of First Corinthians, which includes one of the Bible's greatest passages on the meaning of love. It's often read at weddings -- and rightly so, because it is both profound and practical. (You can read it for yourself in 1 Corinthians 13:4-13.)
Apparently, however, he was reading from an older translation of the Bible that uses an old English word, "charity," instead of its modern equivalent, "love." Over the centuries, some words can change their meaning, and that's the case here with the word "charity." If you do read the passage from an old translation (e.g., the King James Version), simply substitute the word "love" for the word "charity," and you'll understand its meaning.
Within those few verses, the Bible lists some 15 characteristics of true love (far more than I can list here). Some of them are positive -- that is, they tell us what love does (e.g., it's always patient and kind). Others are negative -- that is, they tell us what love does not do (e.g., it's never rude or self-seeking). How different our marriages (and our lives) would be if we put them into action! And we can, with God's help.
Our understanding of love doesn't just come from a list, however. It comes most of all from Jesus Christ, who showed us the meaning of God's love by dying on the cross for us. "This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins" (1 John 4:10).