But if I tarry long (ean de bradunw). Condition of third class with ean and the present active subjunctive of bradunw, old verb, to be slow (usually intransitive), from bradu (slow, dull, Luke 24:25 ), in N.T. only here and 2 Peter 3:9 . That thou mayest know (ina eidh). Final clause with ina and second perfect active subjunctive of oida, to know. How men ought (pw dei). "How it is necessary for thee" (supply se more naturally than tina, any one). Indirect question. To behave themselves (anastrepesqai). Present middle (direct) infinitive of anastrepw, old verb, to turn up and down. See 2 Corinthians 1:12 ; Ephesians 2:3 . In the house of God (en oikwi qeou). Probably here "household of God," that is "the family of God" rather than "the house (or temple) of God." Christians as yet had no separate houses of worship and oiko commonly means "household." Christians are the nao (sanctuary) of God ( 1 Corinthians 3:16 ; 2 Corinthians 6:16 ), and Paul calls them oikeioi tou qeou ( Ephesians 2:19 ) "members of God's family." It is conduct as members of God's family (oiko) that Paul has in mind. Which (hti). "Which very house of God," agreeing (feminine) with the predicate word ekklhsia (church). The church of the living God (ekklhsia qeou zwnto). Probably here the general church or kingdom as in Colossians and Ephesians, though the local church in verse Ephesians 5 . The pillar and ground of the truth (stulo kai edraiwma th alhqeia). Paul changes the metaphor again as he often does. Those words are in apposition to ekklhsia and oiko. On stulo, old word for pillar, see Galatians 2:9 ; Revelation 3:12 (only other N.T. examples). Hedraiwma, late and rare word (from edraiow, to make stable) occurs here first and only in ecclesiastical writers later. Probably it means stay or support rather than foundation or ground. See 1:23 ; 2 Timothy 2:19 for similar idea. See also Matthew 16:18 .