Malachi 4

Behold, I will send you Elijah the prophet
Before the coming of the great and dreadful day of the Lord.
6 And he will turn
The hearts of the fathers to the children,
And the hearts of the children to their fathers,
Lest I come and strike the earth with a curse.” vv.5-6

Read chapter 4
Would you say that Christ's first coming on this earth was a great and dreadful day?  If you know about Jesus you know that He came to save the world in His first coming, He did not judge or take vengeance on His enemies, rather He forgave them and died for them.  
So then why do people say that John the Baptist is reincarnated Elijah coming back to fill this prophesy?  First off we never read of reincarnation in the Bible.  Well we see words of Jesus in Matthew 11:13-14 say that he is, "For all the prophets and the law prophesied until John.  And if you are willing to receive it, he is Elijah who is to come." 
but then we also see John the Baptist flat out say he is not in John 1:21,  "And they asked him, “What then? Are you Elijah?” He said, “I am not.” “Are you the Prophet?” And he answered, “No.”
So why does there seem to be contradiction?  One thing we lose sometimes in translation are indefinite articles we have in English that aren't in Greek; the word 'a'.  The verse quoting Jesus should read better "he is an Elijah."  This makes sense also when the angle tells Zechariah that his son (John the Baptist) will come in the spirit and power of Elijah (Luke 1:17), but not Elijah himself.  Jesus is saying that just as it will be in the future day of the Lord when rebels will not even listen to Elijah, this test of someone similar to what Elijah will do they've already failed.
But oh what a beautiful time that will be of hearts of fathers and children turning toward each other, for just as a child is eager to learn and believe so too in adults- a sad thing that that goes away today as we get older.  
What is your opinion on reincarnation?  How have you lost your childlike heart of belief and desire for the Lord?  How can you still retain it as you grow older?