Adam Clarke on 2 Thessalonians 3:2

Unreasonable and wicked men - The word ατοπων, which we translate unreasonable, signifies rather disorderly, unmanageable; persons out of their place - under no discipline, regardless of law and restraint, and ever acting agreeably to the disorderly and unreasonable impulse of their own minds.

For all men have not faith - The word πιστις is without doubt, to be taken here for fidelity or trustworthiness, and not for faith; and this is agreeable to the meaning given to it in the very next verse: But the Lord is faithful, πιστος δε εστιν ὁ Κυριος.

There are many, even of those who have received a measure of the Divine light, in whom we cannot confide; they are irregular, disorderly, and cannot be brought under regular discipline: to these we cannot trust either ourselves or any thing that concerns the cause of God. But the Lord is worthy of your whole confidence; doubt him not; he will establish you, and keep you from any evil to which you may be exposed by these or such like persons.