Hodge on power of God

“When we are really weak in ourselves and are conscious of that weakness, we are in the state suited to the manifestation of God’s power. When we are emptied of ourselves, we are filled with God. Those who think they can change their own hearts, atone for their own sins, subdue the power of evil in their own souls or in the souls of others, who feel able to sustain themselves under affliction, God leaves to their own resources. But when they feel and acknowledge their weakness, he imparts divine strength to them.” Charles Hodge

Boston on power of God in evangelism

"Acknowledge thine own weakness and uselessness without God's grace, and so cry incessantly for it, that the Lord may drive the fish into the net, when thou art spreading it out. Have an eye to this power, when thou art preaching; and think not thou to convert men by the force of reason: if thou do, thou wilt be beguiled." Thomas Boston