Luke 3:16, “John said, ‘I am just baptizing with water. But someone more powerful is going to come, and I am not good enough even to untie his sandals. He will baptize you with the Holy Spirit and with fire.'” CEV
“Untie his sandals: This was the duty of a slave.” CEV Bible Notes
John did not feel he was good enough to be the slave of Jesus. None of us are good enough. It is Jesus in us that is good.