John 12:9-11  Much people of the Jews therefore knew that he was there: and
they came not for Jesus' sake only, but that they might see Lazarus also, whom
he had raised from the dead. But the chief priests consulted that they might put
Lazarus also to death; Because that by reason of him many of the Jews went away,
and believed on Jesus.
Reason can have multiple meanings, as seen in a few of the definitions.

–noun

a basis or cause, as for some belief, action, fact, event, etc. 
a statement presented in justification or explanation of a belief or action.
the mental powers concerned with forming conclusions, judgments, or inferences. 

 
-verb
 to think or argue in a logical manner. 

     As a noun, you can have a reason, give a reason, and use your reason. As a verb, you can reason out or with. Either way, to say the "reason is because" in a sentence  is criticized  as redundant. The word because  (literally, by cause ) contains within it the meaning of reason;  therefore saying "the reason is because"  is like saying “The cause is by cause,” But, as one of the usual features of  the 1611 King James Bible, redundancy is prized as a teaching method of repetition. It is a key feature that you can find a synonym just after the new words used in their first occurances. For example, when the KJV1611 uses collops of fat, fat tells you what collops are more commonly called. This could be looked at as redundant in today's language, but the feature helped generations of Americans learn to read using the Bible as a reader. I am not promoting this method of learning to read. But, it was used, and it worked at that time. I think it illustrates that redundancy has a purpose in more than just poetry and song. 
    Joseph Glanvill, an English writer said, "The belief of our Reason is an Exercise of Faith, and Faith is an Act of Reason." We are using our intellectual powers of reasoning when we have faith in God. The passage from John 12 above gives reasons that people came to hear Jesus. I haven't throughly researched all the reasons people came to see Jesus, but I can say off the top of my head that the majority of reasons had to do with the miracles He performed for and through people. In fact, that is the reason given here. They came because Jesus had raised a man from the dead. They wanted to see this dead man walk and talk. And, they wanted to start trouble for Jesus and kill Lazarus because of the Jews that had fallen away from the temple and were following Jesus.
     Imagine that! They wanted to kill Lazarus because he was healed! He was a dead man walking and he was about to be a dead man walking. What were they thinking? If Jesus had brought a dead man back to life, how did they think they were going to kill him again? And, how were they going to kill a man who could raise the dead? It is unimaginable. But, Lazarus caused all this grief. He made Jesus a wanted man...wanted dead.
     We have our reasons for seeking and believing in Jesus. And, Jesus had His reasons for seeking us out through His death, burial, and resurrection. Our human powers of reason are often at a loss to explain Jesus' reasons. Suffice it to say, He loved us. That is reason enough.