Stephen Charnock says it well:
The fears and anxieties in the consciences of men have given men sufficient occasion to root it (the knowledge of God, LK) out, had it been possible for them to do it. If the notion of the existence of God had been possible to have been dashed out of the minds of men, they would have done it rather than have suffered so many troubles in their souls upon the commission of sin; since they did not want wickedness and wit in so many corrupt ages to have attempted it and prospered in it, had it been possible...It seems to be so perpetually fixed, that the devil did not think fit to tempt man to the denial of the existence of a deity, but persuaded him to believe, he might ascend to that dignity, and become a god himself...He (Satan, LK) wanted not malice to raze out all the notions of God, but power; he knew it was impossible to effect it, and therefore in vain to attempt it...The impressions of a deity were so strong as not to be struck out by the malice and power of hell. (Works of Stephen Charnock, volume 1, pp. 136-7).