Thinketh himself to be religious (dokei qrhsko einai). Condition of first class (ei-dokei). Trhsko (of uncertain etymology, perhaps from qreomai, to mutter forms of prayer) is predicate nominative after einai, agreeing with the subject of dokei (either "he seems" or "he thinks"). This source of self-deception is in saying and doing. The word qrhsko is found nowhere else except in lexicons. Hatch (Essays in Biblical Greek, pp. 55-57) shows that it refers to the external observances of public worship, such as church attendance, almsgiving, prayer, fasting ( Matthew 6:1-18 ). It is the Pharisaic element in Christian worship. While he bridleth not his tongue (mh calinagwgwn glwssan eautou). "Not bridling his own tongue." A reference to verse Matthew 19 and the metaphor is repeated in Matthew 3:12 . This is the earliest known example of the compound calinagwgew (calino, bridle ago, to lead). It occurs also in Lucian. The picture is that of a man putting the bridle in his own mouth, not in that of another. See the similar metaphor of muzzling (pimow) one's mouth ( Matthew 22:12epimwqh). Deceiveth (apatwn). Present active participle from apath (deceit). He plays a trick on himself. Religion (qrhskeia). Later form of qrhskih (Herodotus) from qrhsko above. It means religious worship in its external observances, religious exercise or discipline, but not to the exclusion of reverence. In the N.T. we have it also in Acts 26:5 of Judaism and in Colossians 2:18 of worshipping angels. It is vain (mataio, feminine form same as masculine) or empty. Comes to nothing.