The Greek in Mark 4:11 that is translated as “to you has been given the secret of the kingdom of God” or similar in English is translated in the German New Testament translation by Berger / Nord (publ. 1999) as unter euch ist Gottes Herrschaft unsichtbar, als Geheimnis, gegenwärtig or “God’s reign is present among you, invisibly, as a mystery.”

In a footnote they explain: “Literally: ‘The secret of the kingdom of God has been given to you.’ This does not refer to understanding, because the disciples clearly still lacked that. The word ‘mystery’ [or: secret] refers to the state of the kingdom, not to the disciples’ knowledge.”