Clement of Alexandria

If we are called to the kingdom of God, let us walk worthy of the kingdom, loving God and our neighbor. Love is not proved by a kiss but by kindly feeling. But there are those who do nothing but make the church resound with a kiss, not having love itself inside them. For this very thing, the shameless use of a kiss, which ought to be mystic, occasions foul suspicions and evil reports. The apostle, however, calls the kiss holy.