Whenever ungodly men take offense at the preaching of the divine Word in such a manner that the more they hear, the more they resist the Holy Spirit, they are said to harden their hearts against the divine truth, Ex. 8, 15; Ps. 95, 8; John 12, 40. In the process of hardening degrees may be recognized, so that not every case of obduracy is beyond recovery, Acts 3, 14-17. As God is not the cause of the offense which is taken at His Word, so He is not the cause of the hardening of those who refuse to believe, Acts 7, 51-54, though Scripture speaks also of obduration as an act of God, Ex. 7, 3; Rom. 1, 24-26. The direct cause of obduration iB a) the devil, who blinds the human mind and fills the heart with wickedness, 2 Cor. 4, 4; Acts 5, 3; Eph. 2, 2; and b) man himself, who of his own will rejects divine grace, Matt. 13, 15; 23, 37, while God hardens man not causally, but judicially and permissively, Rom. 1, 24. 26; Acts 7, 42. Hence the divine act of obduration may be described as a judicial act of God by which, on account of antecedent, voluntary, and persistent wickedness, He justly permits the obstinate sinner to harden himself by withdrawing from him His Holy Spirit and delivering him into the power of Satan, Luke 22, 3.