Did Jesus keep secrets from the Twelve in Luke 18 until He was ready to reveal them?

Yes. Luke 18 records that Jesus took the Twelve aside near the end of His earthly ministry and told them they were going up to Jerusalem, where all things written by the prophets concerning the Son of Man would be accomplished. The context states God kept things secret from the Twelve until He was ready to reveal them.

Les explains that Deuteronomy 29:29 establishes God's prerogative: the secret things belong to the LORD, while the revealed things belong to us and our children. Revelation and secrecy go together, and God does not reveal everything all at once but at the right time. Turning to Luke 18:31, near the end of Jesus' earthly ministry, just before going up to Jerusalem, He took the Twelve and said all things written by the prophets concerning the Son of Man would be accomplished. Les says this shows God actually kept things secret from the Twelve that they did not understand until He was ready to reveal it. Prophecy had to be fulfilled.

Luke 18:31

Then he took unto him the twelve, and said unto them, Behold, we go up to Jerusalem, and all things that are written by the prophets concerning the Son of man shall be accomplished.

Did Jesus keep things secret from the twelve disciples?

Yes. The context states God kept things secret from the Twelve that they did not understand until He was ready to reveal it. In Luke 18, Jesus took the Twelve aside and spoke of what the prophets wrote about the Son of Man, yet the secret remained until God's timing.