In the ancient world a kiss was given not just to one’s spouse and close family. It was a sign of respect in addition to being a sign of love. At Mass the clergy kiss the altar and the Book of the Gospels as signs of love and respect for these holy objects and what they symbolize.
When a priest vests for Mass he kisses his stole before putting it on. The stole is a symbol of the office of priesthood into which he has been ordained. A priest at Mass acts in persona christi, it is an awesome mystery and a great privilege. His kiss of the stole is a sign of respect for the office to which God has called him.
