Building up (epoikodomounte). Present active participle of epoikodomew, old compound with metaphor of a house (oiko), common in Paul ( 1 Corinthians 3:9-17 ; Colossians 2:7 ; Ephesians 2:20 ). On your most holy faith (th agiwtath umwn pistei). For the spiritual temple see also 1 Peter 2:3-5 . See pisti (faith) in this sense (cf. Hebrews 11:1 ) in 2 Peter 1:5 with the list of graces added. A true superlative here agiwtath, not elative. Praying in the Holy Spirit (en pneumati agiwi proseucomenoi). This is the way to build themselves up on their faith.