What does Mark 4:22 mean?
In the parable of the sower (Mark 4:1–9), the "seed" is Jesus' parables. His parables contain truths that until this time have been hidden. Some of those truths include who the Messiah is, what the Messiah has come to do, and how God plans to save His people. With the coming of Jesus' ministry, it is time to uncover those secrets.Jesus' intent for how the truth is to be made manifest is specific: not by demons (Mark 1:24–26, 34; 3:11–12), not in the wrong time (John 2:4; 7:8), and by apostles who have been specially chosen and trained (Mark 3:13–19). The disciples will not be able to reveal too much until Jesus has been resurrected (Mark 9:9). Some of the secrets, like that salvation is also for the Gentiles, will stay hidden until after Jesus' ascension (Ephesians 3:6).
At this time, the Roman Empire is inundated by "mystery religions." These are belief systems that initiates learn gradually as they rise through the ranks of the organization. Examples include the Cult of Cybele, the Mysteries of Isis, and the Mithraic Mysteries.
While mystery religions only reveal their secrets to the faithful, Jesus is just waiting on timing. His followers won't understand He is the Messiah until they see His miracles. They won't understand salvation until after the resurrection. They won't understand the church until after His ascension. And they won't understand that salvation is for all people until they see Gentiles converted.
In the church age, the light to be revealed is Jesus (John 9:5) and we are commissioned to shine that light (Matthew 28:19–20). We will meet persecution, but refusing to obey God is worse than death (Matthew 10:26–28). Unlike the pagan religions, Jesus' mysteries are available for anyone who wants them, in any degree they wish to understand (Mark 4:24–25, 33).