Robertson's Word Pictures (NT)
Building up (epoikodomountev). Present active participle of epoikodomew, old compound with metaphor of a house (oikov), common in Paul (I 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 I Peter 2:3-5. See pistiv (faith) in this sense (cf. Hebrews 11:1) in II Peter 1:5 with the list of graces added. A true superlative here agiwtath, not elative.
Praying in the Holy Spirit (en pneumati agiw proseuxomenoi). This is the way to build themselves up on their faith.
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