St. Paul's hymn to love in 1 Corinthians 13 is by far the most popular reading for weddings, but the love Paul praises is not romantic love. It is the gracious, unearned love with which God loves us and expects us to pass on to others. God loves us, not because of who we are, but because of who God is. God enables us to love others not because of who they are, but because God's unearned love within us pushes us out in love for all human beings.
This hymn to love as the 2nd reading this Sunday illuminates the Gospel's emphasis on universal salvation.