Colossians 1 26
That message is a secret that God hid from everyone before now. He hid it from all the people who lived in past times. But now he has shown this secret to his people.
Compare with other 3 random translations
NAS Colossians 1:26that is, the mystery which had been hidden from the past ages and generations, but now has been revealed to His saints,
NIV Colossians 1:26the mystery that has been kept hidden for ages and generations, but is now disclosed to the Lord’s people.
CSB Colossians 1:26the mystery hidden for ages and generations but now revealed to his saints.