Albert Barnes Commentary 2 Corinthians 6:7

"in the word of truth, in the power of God; by the armor of righteousness on the right hand and on the left," — 2 Corinthians 6:7 (ASV)

By the word of truth. That is, by making known the truths of the gospel. It was his object to make known the simple truth. He did not corrupt it with false mixtures of philosophy and human wisdom, but communicated it as it had been revealed to him. The object of the appointment of the Christian ministry is to make known the truth; and when that is done, it is inevitable that they will commend their office and work to the favorable regard of people.

By the power of God. By the Divine power that attended the preaching of the gospel. Most of the ancient commentators explain this as referring to the power of working miracles—Bloomfield. But it probably includes all the displays of Divine power that attended the propagation of the gospel, whether in the working of miracles or in the conversion of people. If it is asked how Paul used this power so as to give no offense in the work of the ministry, it may be answered that the miraculous endowments bestowed upon the apostles, the power of speaking foreign languages, etc., seem to have been bestowed upon them to be used in the same way as their natural faculties. See Barnes on 1 Corinthians 14:32.

The idea here is that they used the great powers entrusted to them by God, not as impostors would have done—for the purposes of gain and ambition, or for vain display—but solely for the furtherance of the true religion and the salvation of people. They thus showed that they were sent from God, both by the nature of the powers with which they were entrusted and by the manner in which they used them.

By the armor of righteousness on the right hand and on the left. Interpreters have varied much in the interpretation of this passage, and many have ventured into wild speculation. Grotius says that it refers to the manner in which ancient soldiers were armed: they bore a spear in their right hand and a shield in their left.

With the former, they attacked their enemies; with the latter, they defended themselves. Some have supposed that it refers to the fact that they were taught to use the sword with the left hand as well as with the right. The simple idea is that they were completely armed. To be armed on the right hand and on the left is to be well armed, or entirely equipped.

They went out to conflict. They met persecution, opposition, and slander. As the soldier went well armed to battle, so did they. But the armor with which they met their enemies, and which constituted their entire panoply, was a holy life. With that they met all the assaults of their enemies; with that, all slander and persecution.

That was their defense, and by that they hoped and expected to achieve their conquests. They had no swords, and spears, and helmets, and shields; no carnal weapons for offense and defense; but they expected to meet all their assaults and to gain all their victories by an upright and holy life.