Jer 1:5 Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations.
Jer 1:6 Then said I, Ah, Lord GOD! behold, I cannot speak: for I am a child.
Jer 1:7 But the LORD said unto me, Say not, I am a child: for thou shalt go to all that I shall send thee, and whatsoever I command thee thou shalt speak.
Jer 1:8 Be not afraid of their faces: for I am with thee to deliver thee, saith the LORD.
Jeremiah was chosen from the womb. Moses too was so chosen, and he was called at the burning bush to a great ministry. Common to both was their reluctance, because they knew in themselves that they were not enough. Sometimes we say no to God, when we should say yes. We each have giftings to be used for God. Next time you are asked to do something greater than yourself, trust God and say yes. That is what the walk of faith is all about.