Mar 4:22 For there is nothing hid, which shall not be manifested; neither was any thing kept secret, but that it should come abroad.
For there is nothing secret which shall not be made clear, nor is it made hard to see except on its way to to making it visible.
In the Greek, the relationship between the words for "hid" and "secret" is clearer with the later as a more extreme form of the first. The sense of the line is clearer in my alternative above where I try to get as close as possible to the original meaning of the verbs.
Christ is explaining here in more detail why he uses parables. He makes ideas hard to understand so that they can become clear over time. If he said his ideas openly, they would could become corrupted over time because the meaning of the words would change.
There is a sense here that the truth must be put in a flawed, physical form in order to preserve and maintain it and allow people to discover it over time. It is like a gift that we must unwrap. Parables, in a sense, reflect Christ's idea of the spiritual hidden inside the physical giving rise to the intellectual and emotional.
In this, parables are like the human body. Our bodies are wrappers for our souls hidden within them. Our hidden thoughts and feelings are known only to God, but those thoughts and feelings can preserve our soul and set it free. The soul is hidden, but our spirit expresses itself in everything we say or do. The spirits that have eternal life are those that hear the truth and learn to produce fruit from it.
"Hid" and "secret" have the same root, with the later as a more extreme form of the first.
"Neither" is from oude (oude), which means "but not", "and not", "nor", "not even," and "no not." "Was anything kept" is fromgignomai (ginomai), which means "to become", "to come into being", "to be produced," and "to be."
"It should come" is from erchomai, (erchomai) which means "to start", "to set out", "to arrive at", "to come" and "to go." It generally refers to any kind of motion. It is a little like we use the phrase "he is on his way," which can mean either that he is coming or going with no direct reference to coming to or going from the position of the speaker.