“The human heart knows not the vacuity that has been made in it by the absence of God; it knows not the malignity of one single sin—one single act of disobedience, one moment’s insubordination of the will, one moment’s ceasing to love God with all the heart and soul. Unconsciousness of his own need; insensibility to his own sin; palsy of the conscience—this is man’s great evil’” (Horatius Bonar 1869)