Mark 1:15

ἡ βασιλεία τ. θ.: this defines more precisely the gospel Jesus preaches. It is the gospel of the Kingdom of God. But even this is vague. The kingdom may be differently conceived: as an awful thing or as a beneficent thing. The summons following throws light on its nature. μετανοεῖτε καὶ πιστεύετε : “repent” echoes John's preaching, and savours of awe, but “ believe ” is a new word, and presumably the watchword of the new ministry. And the name for the message to be believed settles the nature of the kingdom. Its coming is good news (ἐν τῷ εὐαγγελίῳ). For πιστεύειν ἐν, vide Galatians 3:26; Ephesians 1:13.