Charles H. Spurgeon on Psalms 17:12

Lions are not more greedy, nor their ways more cunning than are Satan and his helpers when engaged against the children of God. The blood of souls the adversary thirsts after, and all his strength and craft are exerted to the utmost to satisfy his detestable appetite. We are weak and foolish like sheep; but we have a shepherd wise and strong, who knows the old lion's wiles, and is more than a match for his force; therefore will we not fear, but rest in safety in the fold. Let us beware, however, of our lurking foe; and in those parts of the road where we feel most secure, let us look about us lest, peradventure, our foe should leap upon us.