The Bible story of Gideon illustrates beautifully that God is not looking for yes-men. Gideon was called to lead the Israelites against their oppressors, the Midianites, after seven years of tyranny. Gideon's response was, "Who? Me? You've got to be kidding! I'm not qualified." The angel messenger, who appeared as a stranger passing through, then gave Gideon a sign: when an elaborate dinner was place before the visitor on a rock, it exploded into fire and the angel disappeared. This convinced Gideon that the messenger was legit, and he followed instructions to break down some of the pagan altars among his own people.
But when the enemy gathered in huge numbers in the valley before him, and Gideon was told that now was the time, he pushed back and asked for a sign, and then another! First he left a fleece out over night and asked that it be drenched with dew, but not the ground around it. When that sign was given, he then asked for the reverse, a dry fleece with wet ground. Okay. Now he was convinced that it was not his imagination or ego driving him.
God then required that he reduce Gideon's army of many thousands to a band of 300 so that there would be no doubt as to who overcame the massive armies of the enemy. And finally, God wanted to be sure there was not a doubt left in Gideon's thought so He encouraged him to sneak down to the enemy camp at night and spy out the situation. He over-heard a man recounting a dream, interpreting it to be Gideon conquering them!! That gave Gideon full confidence in his mission, and he proceeded to lead his band to quick victory.
We can draw from this story that the humility of Gideon, his total lack of self-confidence, his apparent purity of thought, enabled him to be used by the divine Intelligence. He could not and would not take responsibility until he was utterly convinced that God was working through him. A yes-man would surely have failed when the enormity of his task kicked in and the lack of depth in his conviction surfaced.