4:17 A Weapon - This is to be taken figuratively; being a proverbial speech, as when they say of a man pretending kindness, he carries bread in one hand, and a stone in another. Thus must we work out our salvation, with the weapons of our warfare in our hands. For in every duty we must expect opposition from our spiritual enemies.
4:16-23 We must watch always against spiritual enemies, and not expect that our warfare will be over till our work is ended. The word of God is the sword of the Spirit, which we ought to have always at hand, and never to have to seek for it, either in our labours, or in our conflicts, as Christians. Every true Christian is both a labourer and a soldier, working with one hand, and fighting with the other. Good work is likely to go on with success, when those who labour in it, make a business of it. And Satan fears to assault the watchful Christian; or, if attacked, the Lord fights for him. Thus must we wait to the close of life, never putting off our armour till our work and warfare are ended; then we shall be welcomed to the rest and joy of our Lord.
