World Wide Study Bible
a Bible passage
5For this reason, when I could bear it no longer, I sent to find out about your faith; I was afraid that somehow the tempter had tempted you and that our labor had been in vain.
5 Lest perhaps the tempter has tempted you. By this term he teaches us that temptations are always to be dreaded, because it is the proper office of Satan to tempt. As, however, he never ceases to place ambushes for us on all sides, and to lay snares for us all around, so we must be on our watch, eagerly taking heed. And now he says openly what in the outset he had avoided saying, as being too harsh — that he had felt concerned lest his labors should be vain, if, peradventure, Satan should prevail. And this he does that they may be carefully upon their watch, and may stir themselves up the more vigorously to resistance.