Idleness.
Some temptations come to the industrious, but all temptations attack the idle. Idle Christians are not tempted of the devil so much as they do tempt the devil to tempt them. Idleness sets the door of the heart ajar, and asks Satan to come in; but if we are occupied from morning till night, should Satan get in, he must break through the door. Under sovereign grace, and next to faith, there is no better shield against temptation than obedience to the precept, that ye be "Not slothful in business; fervent in spirit; serving the Lord."