John Calvin Commentary 1 Timothy 3:7

"Moreover he must have good testimony from them that are without; lest he fall into reproach and the snare of the devil." — 1 Timothy 3:7 (ASV)

A good report from those who are without. This appears to be very difficult: that a godly man should have as witnesses of his integrity infidels themselves, who are furiously driven to slander us. But the apostle means that, as far as external behavior is concerned, even unbelievers themselves shall be constrained to acknowledge him to be a good man; for, although they groundlessly slander all the children of God, yet they cannot pronounce him to be a wicked man who leads a good and inoffensive life among them. Such is the acknowledgment of uprightness that Paul here describes. The reason is added,—

Lest he fall into reproach and the snare of the devil; which I explain in this manner: “lest, being subject to reproach, he begin to be hardened and more freely abandon himself to all iniquity, which is to entangle himself in the devil’s snares.” For what hope is left for him who sins without any shame?