“I remember my earliest days as a Christian, when there came to my mind thoughts so evil that I clapped my hand over my mouth for fear I should be led to give utterance to them. This is one way in which Satan tortures those whom God has delivered from his hands. Many of the choicest saints have been so molested.
Once when I had been grievously assailed by the tempter, I went to see my dear old grandfather. I told him about my terrible experience and I wound up by saying: “I am sure I cannot be a child of God or else I should never have such thoughts.”
“Nonsense Charles”, replied the good old man; it is just because you are a Christian, you are so tempted. These are the devils brats, which he delights to leave at the door of a Christian. Don’t you own them as yours, give them neither heart-room nor head-room”
– Charles Haddon Spurgeon
Cf: Gen 4:7 = behold sin lieth at the door, and its desire is for you, BUT YOU RULE OVER IT!