question his all-sufficiency, as though he were not able to accomplish the promises he had made to them, Josh. vii. 7, 8, 9. (5.) When we doubt of the truth, or certain accomplishment of his promises, and so are ready to say, _Hath God forgotten to be gracious? Doth his truth fail for ever?_ This we are apt to do, when there are great difficulties in the way of the accomplishment thereof: thus Sarah, when it was told her that she should have a child, in her old age, laughed, through unbelief, Gen. xviii. 12. and God intimates, that this was an affront to his all-sufficiency, when he says, _Is any thing too hard for the Lord?_ ver. 14. and Gideon, though he was told that God was with him, and had an express command to go in his might, with a promise that he should deliver Israel from the Midianites, yet he says, _O Lord wherewith shall I save them? for my family is poor in Manasseh, and I am the least in my father’s house_, Judg. vi. 15. God tells him again, _I will be with thee, and smite the Midianites_, ver. 16. yet, afterwards, he desires that he would give him a sign in the wet and dry fleece. What is this but questioning his all-sufficiency? (6.) When we decline great services, though called to them by God, under pretence of our unfitness for them: thus when the prophet Jeremiah was called to deliver the Lord’s message to the rebellious house of Israel, he desires to be excused, and says, _Behold I cannot speak, for I am a child_; whereas the main discouragement was the difficulty of the work, and the hazards he was like to run; but God encourages him to it, by putting him in mind of his all-sufficiency, when he tells him, that _he would be with him, and deliver him_, Jer. i. 6. compared with ver. 8.