Article XIX: Of the Cause of Sin

77] The Nineteenth Article the adversaries receive, in which we confess that, although God only and alone has framed all nature, and preserves all things which exist, yet (He is not the cause of sin, but] the cause of sin is the will in the devil and men turning itself away from God, according to the saying of Christ concerning the devil, John 8:44: When he speaketh a lie, he speaketh of his own.

Source.