A cautionary direction, 'be strong in the Lord.’
In this we have a cautionary direction. Having exhorted the saints at Ephesus, and in them all believers, to a holy resolution and courage in their warfare, lest this should be mistaken, and beget in them an opinion of their own strength for the battle, the apostle leads them out of themselves for this strength, even to the Lord: 'be strong in the Lord.’ From whence we observe.
[The saint's strength lies in the Lord.]
Doctrine. That the Christian's strength lies in the Lord, not in himself. The strength of the general in other hosts lies in his troops. He flies, as a great commander once said to his soldiers, upon their wings; if their feathers be clipped, their power broken, he is lost; but in the army of saints, the strength of every saint, yea, of the whole host of saints, lies in the Lord of hosts. God can overcome his enemies without their hands, but they cannot so much as defend themselves without his arm. It is one of God's names, 'the Strength of Israel,’ I Sam. 15:29. He was the strength of David's heart; without him this valiant worthy (that could, when held up in his arms, defy him that defied a whole army) behaves himself strangely for fear, at a word or two that dropped from the Philistine's mouth. He was the strength of his hands, 'He taught his fingers to fight,’ and so is the strength of all his saints in their war against sin and Satan. Some propound a question, whether there be a sin committed in the world in which Satan hath not a part? But if the question were, whether there be any holy action performed without the special assistance of God concurring, that is resolved, 'Without me ye can do nothing,’ John 15:5. Thinking strength of God, 'Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God,’ II Cor. 3:5. We apostles, we saints that have habitual grace, yet this lies like water at the bottom of a well, which will not ascend with all our pumping till God pour in his exciting grace, and then it comes. To will is more than to think, to exert our will into action more than both. These are of God: 'For it is God which worketh in you both to will and to do of his good pleasure,’ Php. 2:13. He makes the heart new, and having made it fit for heavenly motion, setting every wheel, as it were, in its right place, then he winds it up by his actuating grace, and sets it on going, the thoughts to stir, the will to move and make towards the holy object presented; yet here the chariot is set, and cannot ascend the hill of action till God puts his shoulder to the wheel: 'to will is present with me; but how to perform that which is good I find not,’ Rom. 7:18. God is at the bottom of the ladder, and at the top also, the Author and Finisher, yea, helping and lifting the soul at every round, in his ascent to any holy action. Well, now the Christian is set on work, how long will he keep close to it? Alas, poor soul, no longer than he is held up by the same hand that empowered him at first. He hath soon wrought out the strength received, and therefore to maintain the tenure of a holy course, there must be renewing strength from heaven every moment, which David knew, and therefore when his heart was in as holy a frame as ever he felt it, and his people by their free-will offering declared the same, yet even then he prays, that God would 'keep this for ever in the imagination of the thoughts of the heart of his people, and prepare their heart unto him,’ I Chron. 29:18.
He adored the mercy that made them willing, and then he implores his further grace to strengthen them, and tie a knot, that these precious pearls newly strung on hearts might not slip off. The Christian, when fullest of divine communications, is but a glass without a foot, he cannot stand, or hold what he hath received, any longer than God holds him in his strong hand. Therefore, Christ, when bound for heaven, and ready to take his leave of his children, bespeaks his Father's care of them in his absence. 'Father, keep them,’ John 17:11; as if he had said, they must not be left alone, they are poor shiftless children, that can neither stand nor go without help; they will lose the grace I have given them, and fall into those temptations which I kept them from while I was with them, if they be out of thy eye or arms but one moment; and therefore, 'Father, keep them.’
