When someone says something that edifies his fellow beings, he speaks out of the goodness stored up in his heart, since he himself is good, as the Lord confirms (cf. Luke 6:45). No one can devote himself to theology and speak about what pertains to God unless so empowered by the Holy Spirit; and no one when inspired by the Spirit of God says anything contrary to faith in Christ (cf. 1 Corinthians 12:3).
But he says only what is edifying, only what leads others to God and His kingdom and restores them to their original nobility, bringing them to salvation and uniting them to God. And if ‘the manifestation of the Spirit is given to each to the degree that is profitable’ (1 Corinthians 12:7), this means that anyone enriched with the wisdom of God and blessed with spiritual knowledge is inspired by the divine Spirit and is a storehouse of the inexhaustible treasures of God.
~Nikitas Stithatos
Prayerful Life 