Strong’s says that the biblical Greek word mystery means truth revealed. God hid His plans from the rulers of this world. 1 Corinthians 2:8 says, “…had they known, they would not have crucified the Lord of glory.”

Jesus’ disciples asked Him why He spoke in parables. Matthew 13:11 says, “…Because it has been given to you to know the mysteries of the kingdom of heaven, but to them it has not been given.”

1 Peter 1:10 says that the prophets searched diligently. Verse 11 says, “Searching what, or what manner of time, the Spirit of Christ who was in them was indicating when He testified beforehand the sufferings of Christ and the glories that would follow.” 

He revealed to them that it was to us not them. For example, Daniel 12:9 says, “…Go your way Daniel, for the words are closed up and sealed tell the time of the end.” We live in His revealed truth.