I remember reading a sermon by Charles Spurgeon in which he gave the account of a preacher who was upon his death bed. Some preacher brethren visited him to have prayer and to encourage their brother.

He told them that all during his ministry the devil had tried to turn him from Christ by telling him he had not done enough to enter into the kingdom of God. He then told them that now, as he lay dying, the devil was trying to turn him from depending on Jesus by telling him that if anyone had done enough good works to go to heaven, it was him.

The devil wants us to trust anyone, anything or nothing at all, as long as we don't trust the Savior.