Thou shalt drive out the Canaanites, though they have iron chariots, and though they be strong. -Joshua 17:18
It is a great encouragement to valor to be assured of victory, for then a man goes forth to war in confidence and ventures where else he had been afraid to go. Our warfare is with evil within us and around us, and we ought to be persuaded that we are able to get the victory and that we shall do so in the name of the Lord Jesus. We are not riding for a fall, but to win; and win we shall. The grace of God in its omnipotence is put forth for the overflow of evil in every form: hence the certainty of triumph.
Certain of our sins find chariots of iron in our constitution, our former habits, our associations, and our occupations. Nevertheless we must overcome them. They are very strong, and in reference to them we are very weak; yet in the name of God we must master them, and we will. If one sin has dominion of us we are not the Lord’s free men. A man who is held by only one chain is still a captive. There is no going to heaven with one sin ruling within us, for of the saints it is said, “Sin shall not have dominion over you.” Up, then, and slay every Canaanite, and break to shivers every chariot of iron! The Lord of hosts is with us, and who shall resist His sin-destroying power? ~ C.H. Spurgeon