Unsuspecting (172) (akakos from a = without + kakos = constitutionally bad, morally evil -- see study of related word kakia) literally refers to who are not constitutionally bad. One needs to examine the context of the usage to determine whether this trait is good or bad, as explained below. Akakos can be used in a positive sense as in the passage in Hebrews which describes our Lord Jesus as an innocent (guileless, free from guilt, without guile or fraud) High Priest. Philo uses akakos for newborn infants. Several uses in the LXX use akakos in a positive sense to describe a person of integrity and/or innocence. While a certain kind of simple innocence is good (see note Romans 16:19), that of which Paul speaks here is not good. In Christian infancy "innocence" may be excusable, but we are supposed to outgrow it as we mature in Christ (He 5:11; 5:12; 5:13; 5:14-see notes He 5:11; 12; 13; 14). They would include those who are especially vulnerable to being taken in by fancy talk and flattery. They are unsuspecting, unwary, naïve. Thayer characterizes them as fearing no evil from others, distrusting no one, Godet says they are innocent of evil and easily duped. Murray says these men and women (in Romans 16:18) are "not given to the wiles of deceit” and thus are “not suspecting the same in others”. Bengel feels that akakos is... An indifferent word. They are called so who are merely without positive wickedness, when they ought to abound also in prudence, and to guard against other men’s wickedness. To be called simple-minded or naive in the sense of being easy prey for false teachers is by no means a compliment. The LXX use of akakos in Proverbs 14:15 shows why this trait can leave one vulnerable to these silver tongued snakes... The naive (Hebrew = pethi = simple, foolish; Lxx = akakos) believes everything, but the prudent man considers his steps. (Proverbs 14:15) Akakos is used two times in the NT and 17 times in the Septuagint - LXX (Job 2:3; 8:20; 36:5; Ps. 25:21; Pr 1:4, 22; 2:21; 8:5; 13:6; 14:15; 15:10; 21:11; Jer. 11:19). Below are the NT uses and several representative uses in the LXX... Romans 16:18 For such men are slaves, not of our Lord Christ but of their own appetites; and by their smooth and flattering speech they deceive the hearts of the unsuspecting. Hebrews 7:26 (note) For it was fitting that we should have such a high priest, holy, innocent, undefiled, separated from sinners and exalted above the heavens; Septuagint - LXX... Psalm 25:21 Let integrity (Hebrew = tom = completeness, innocence, simplicity; Lxx = akakos) and uprightness preserve me, For I wait for Thee. Proverbs 1:4 To give prudence to the naive (Hebrew = pethi = simple; Lxx = akakos), To the youth knowledge and discretion, Proverbs 1:22 "How long, O naive ones (Hebrew = pethi = simple; Lxx = akakos), will you love simplicity? And scoffers delight themselves in scoffing, And fools hate knowledge? Proverbs 2:21 For the upright will live in the land, And the blameless (Hebrew = tamiym = complete, sound, wholesome; Lxx = akakos) will remain in it; Proverbs 8:5 "O naive ones (Hebrew = pethi = simple; Lxx = akakos), discern prudence (shrewdness); And, O fools, discern wisdom. Proverbs 13:6 Righteousness guards the one whose way is blameless (Hebrew = tom = completeness, innocence, simplicity; Lxx = akakos), But wickedness subverts the sinner.