A.T. Robertson Commentary Romans 14:17

"for the kingdom of God is not eating and drinking, but righteousness and peace and joy in the Holy Spirit." — Romans 14:17 (ASV)

The kingdom of God (η βασιλεια του θεου). Not the future kingdom of eschatology, but the present spiritual kingdom, the reign of God in the heart, of which Jesus spoke so often. See 1 Corinthians 4:21. Paul scores heavily here, for it is not found in externals like food and drink, but in spiritual qualities and graces.