Or 'acknowledge:' from the same root as 'knowledge' in ch. 2.4.
It means 'intercourse with a person,' then 'petitions and intercession;' one person speaking personally to another. (See Note, ch. 2.1, same Greek word.) The creature, fallen through Adam, belongs to the faithful, and those who know the truth, by God's speaking to them, and their freely speaking to him. This has set all on a new footing, because we have met God again, the word of God having put us into communication by grace. And the 'faithful, and those who know the truth,' have availed themselves of it, and come and enter into intercourse. It is no longer by nature, but by the word of God.