{But the Lord is faithful} (pistos de estin ho kurios).
{But faithful is the Lord} (correct rendition), with a play
(paronomasia) on pistis by pistos as in  Ro 3:3  we have a
word-play on apiste(935c) and apistia. The Lord can be counted on,
however perverse men may be. {From the evil one} (apo tou
pon(8872)ou). Apparently a reminiscence of the Lord's Prayer in  Mt
6:13  
usai h(886d)as apo tou pon(8872)ou. But here as there it is not
certain whether 	ou pon(8872)ou is neuter (evil) like to pon(8872)on
in  Ro 12:9  or masculine (the evil one). But we have ho
pon(8872)os (the evil one) in  1Jo 5:18  and 	ou pon(8872)ou is
clearly masculine in  Eph 6:16 . If masculine here, as is
probable, is it "the Evil One" (Ellicott) or merely the evil man
like those mentioned in verse  2 ? Perhaps Paul has in mind the
representative of Satan, the man of sin, pictured in  2:1-12 , by
the phrase here without trying to be too definite.