'Understood' in the Bible

None of the rulers of this world understood it, because if they had, they would not have crucified the Lord of glory.

The one who is spiritual discerns all things, yet he himself is understood by no one.

For who has known the mind and purposes of the Lord, so as to instruct Him? But we have the mind of Christ [to be guided by His thoughts and purposes].

When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things.

For now [in this time of imperfection] we see in a mirror dimly [a blurred reflection, a riddle, an enigma], but then [when the time of perfection comes we will see reality] face to face. Now I know in part [just in fragments], but then I will know fully, just as I have been fully known [by God].

It is similar for lifeless things that make a sound, like a flute or harp. Unless they make a distinction in the notes, how can what is played on the flute or harp be understood?

So likewise ye, except ye utter by the tongue words easy to be understood, how shall it be known what is spoken? for ye shall speak into the air.