John 3:30 (NKJV)
He must increase, but I must decrease.
John the Baptist had it right. He knew that he was just the messenger and that Jesus was the Message. John the Baptist's disciples were thinking that Jesus was cutting in on their territory and taking followers away from John. For John the Baptist, there was no sense of rivalry; he had a pure sense of humility.
I know that there is a temptation that leaders of the church face today. Success and talents can puff up with pride. So this verse applies to every work done for the Kingdom. Apart from the enablement and work of the Holy Spirit of God all such work would be futile. All is done for Him, by Him, and through Him for God's glory and not our own.
John 15:5 (NKJV)
"I am the vine, you are the branches. He who abides in Me, and I in him, bears much fruit; for without Me you can do nothing.