The following little story is the best analogy about Christian service I have ever read. If you want to be used by God you must empty yourself and let Him fill you. You must have no confidence in yourself or your abilities, you must rely 100% on God and His mercy to carry us through.
The Master was searching for a vessel to use; On the shelf there were many - which one would He choose? "Take me", cried the gold one, "I'm shiny and bright, I'm of great value and I do things just right. My beauty and luster will outshine the rest, And for someone like You, Master, gold would be the best!"
The Master passed on with no word at all; He looked at a silver urn, narrow and tall; "I'll serve You, dear Master, I'll pour out Your drink, and I'll be at Your table whenever You dine, My lines are so graceful, my carvings so true, And my silver will always compliment You."
Unheeding the Master passed on to the brass, It was wide mouthed and shallow, and polished like glass. "Here! Here!" cried the vessel, "I know I will do, Place me on Your table for all men to view."
"Look at me", called the goblet of crystal so clear, "My transparency shows my contents so dear, Though fragile am I, I will serve You with pride, And I'm sure I'll be happy in Your house to abide."
The Master came next to a vessel of wood, Polished and carved, it solidly stood. "You may use me, dear Master", the wooden bowl said, "But I'd rather You used me for fruit, not for Bread!"
Then the Master looked down and saw a vessel of clay. Empty and broken it helplessly lay. No hope had the vessel that the Master might choose, To cleanse and make whole, to fill and to use.
"Ah! This is the vessel I've been hoping to find, I will mend and use it and make it all Mine." "I need not the vessel with pride of its self; Nor the one who is narrow to sit on the shelf; Nor the one who is big mouthed and shallow and loud; Nor one who displays his contents so proud; Not the one who thinks he can do all things just right; But this plain earthy vessel filled with My power and might."
Then gently He lifted the vessel of clay, Mended and cleansed it and filled it that day. Spoke to it kindly, "There's work you must do, Just pour out to others as I pour into you."
"But we have this treasure in earthen vessels, that the excellency of the power may be of God, and not of us."
2 Corinthians 4:7
"Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God."
2 Corinthians 3:5
"But let him that glorieth glory in this, that he understandeth and knoweth me, that I am the LORD which exercise lovingkindness, judgment, and righteousness, in the earth: for in these things I delight, saith the LORD."
"If any man speak, let him speak as the oracles of God; if any man minister, let him do it as of the ability which God giveth: that God in all things may be glorified through Jesus Christ, to whom be praise and dominion for ever and ever. Amen."
1 Peter 4:11
"John answered and said, A man can receive nothing, except it be given him from heaven...He must increase, but I must decrease."
John 3:27, 30
"Now when they saw the boldness of Peter and John, and perceived that they were unlearned and ignorant men, they marvelled; and they took knowledge of them, that they had been with Jesus."
"For ye see your calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, are called: But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty; And base things of the world, and things which are despised, hath God chosen, yea, and things which are not, to bring to nought things that are: That no flesh should glory in his presence. But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption: That, according as it is written, He that glorieth, let him glory in the Lord."
1 Corinthians 1:26-31