John 18:10

10.Then Simon Peter, having a sword, drew it. The Evangelist now describes the foolish zeal of Peter, who attempted to defend his Master in an unlawful manner. Boldly and courageously, indeed, he incurs great risk on Christ’s account; but as he does not consider what his calling demands, and what God permits, his action is so far from deserving praise, that he is severely blamed by Christ. But let us learn that, in the person of Peter, Christ condemns every thing that men dare to attempt out of their own fancy. This doctrine is eminently worthy of attention; for nothing is more common than to defend, under the cloak of zeal, every thing that we do, as if it were of no importance whether God approved, or not, what men suppose to be right, whose prudence is nothing else than mere vanity.

If we saw nothing faulty in the zeal of Peter, still we ought to be satisfied on this single ground, that Christ declares that he is displeased with it. But we see that it was not owing to him that Christ did not turn aside from death, and that his name was not exposed to perpetual disgrace; for, in offering violence to the captain and the soldiers, he acts the part of a highwayman, because he resists the power which God has appointed. Christ having already been more than enough hated by the world, this single deed might give plausibility to all the calumnies which his enemies falsely brought against him. Besides, it was exceedingly thoughtless in Peter to attempt to prove his faith by his sword, while he could not do so by his tongue. When he is called to make confession, he denies his Master; and now, without his Master’s authority, he raises a tumult.

Warned by so striking an example, let us learn to keep our zeal within proper bounds; and as the wantonness of our flesh is always eager to attempt more than God commands, let us learn that our zeal will succeed ill, whenever we venture to undertake any thing contrary to the word of God. It will sometimes happen that the commencement gives us flattering promises, but we shall at length be punished for our rashness. Let obedience, therefore, be the foundation of all that we undertake. We are also reminded, that those who have resolved to plead the cause of Christ do not always conduct themselves so skilfully as not to commit some fault; and, therefore, we ought the more earnestly to entreat the Lord to guide us in every action by the spirit of prudence.