2. Our personal obligation, as Christians, is to be holy; and we want the assurance of faith for that. We may be deceived about our conversion. At the outset of our Christian life we may be the subjects of many illusions. But men are not mistaken when, day by day, they are fighting their passions, bringing the will into subjection, conquering the flesh, and submitting the whole life to the long, slow, toilsome discipline of obedience. This kind of work is never accomplished by a vague and undecided religion. Men do not deny themselves without an equivalent. You cannot persuade them to give up their illusions, their pleasures, their passions, nor even their vices, unless you show them something else which may, must, and ought to take their place. If you empty the heart of one set of elements, you must fill it with another. So it is that we want a living God, a living Christ, close to us; loving us, forgiving us, helping us, comforting us, and opening before us the prospect of glory and of happiness for eternity. Let us know and feel ourselves able to say, "I know whom I have believed, and am persuaded that He is able to keep that which I have committed unto Him against that day," and the struggle with inward evil will be simplified, and will become comparatively easy. 3. We stand in daily need of strength and consolation, and for that nothing but a firm and settled faith will suffice. There are great sorrows and great anxieties to which we are all exposed, in the face of which nothing will do for us but sovereign words of life and of hope in which we can implicitly trust. There are great wrongs under which we cannot be comforted except by the constant conviction of a righteousness which will one day vindicate the right, and redress the wrong. There are great losses in which we want the promise and the certainty of an immense and restoring love. Souls will seek this strength, this consolation, here, there, everywhere; but they will never find it until they can say, "I know whom I have believed, and am persuaded that He is able to keep that which I have committed unto Him against that day." 4. The assurance of faith is necessary to all earnestness of effort in the spread of the gospel. A church or a Christian, subsiding into uncertainty of religious belief, has no motive for zeal in the propagation of religion. We preach because we believe. Let the idea, that the Christianity of Christ or of Paul or of the New Testament needs modification, become prevalent in the professing church, and the secret of every true impulse in missionary work, whether abroad or at home, will be gone. It is the men who share Paul's stable, grand faith who can take their stand as the preachers of Christ. It is only they who can rise to the sacrifices necessary for the promotion of His truth in the world.