The Fifth Head of Doctrine: The Perseverance of the Saints
Article 11: Doubts Concerning This Assurance
Meanwhile, Scripture testifies that believers have to contend in this life with various doubts of the flesh and that under severe temptation they do not always experience this full assurance of faith and certainty of perseverance. But God, the Father of all comfort, does not let them be tempted beyond what they can bear, but with the temptation he also provides a way out (1 Cor. 10:13), and by the Holy Spirit revives in them the assurance of their perseverance.
Article 12: This Assurance as an Incentive to Godliness
This assurance of perseverance, however, so far from making true believers proud and carnally self-assured, is rather the true root of humility, of childlike respect, of genuine godliness, of endurance in every conflict, of fervent prayers, of steadfastness in crossbearing and in confessing the truth, and of well-founded joy in God. Reflecting on this benefit provides an incentive to a serious and continual practice of thanksgiving and good works, as is evident from the testimonies of Scripture and the examples of the saints.
Daily Confession 