does the pslam 51:5 teach the orgnal sin?

• does the pslam 51:5 teach the orgnal sin?

  
  
  ESV translation of the said verse:
  
  Behold, I was brought forth in iniquity, and in sin did my mother conceive me.
  
  As you can see for yourself, this verse is not teaching the Original Sin, it seems to be about the sinful act of adultery yielding a child; the Psalm is thought to be a projection upon the future child of an adulterous relationship.
  
  However, the NIV translation does seem to teach a branch of the Original Sin (i.e. babies are with sin):
  
  Surely I was sinful at birth, sinful from the time my mother conceived me.
  
  So which translation is correct?
  
  Firstly, if the NIV translation (the one teaching Original Sin) is correct then the Bible-believing Christians will have contradictions on their hands. The verses mentioned in the opening article on the topic of Original Sin (Ezekiel 8:4 and 20, 2 Kings 14:6) would be deemed as contradicting Psalm 51:5, thus further discrediting the Bible.
  
  However, in my research of Psalm 51:5 I have found three more verses (from the OT) which seem to refute the idea of Original Sin. The first two go together(Jeremiah 3:25 and Genesis 8:21); they appear to indicate a human only becomes sinful from his/her youth, i.e. at the time of discernment between right and wrong (good and evil). In fact Jeremiah 3:25 indicates humans sin from their youth onwards, thus the idea of Original Sin upon babies seems to be in real question here.
  
  This age of discernment between good and evil appears to be mentioned in Isaiah 7:15-16 as well.
  
  The NIV translation seems to be in error and appears to be unfaithful as the NASB, ESV and KJV all disagree with the NIV translation. The three aforementioned translations all indicate the child was conceived in sin UNLIKE the NIV which suggests the child was sinful at the time of birth.
  
  New American Standard Bible (NAS:
  
  Behold, I was (A)brought forth in iniquity,And in sin my mother conceived me.
  
  King James Version (KJV):
  
  Behold, I was shapen in iniquity; and in sin did my mother conceive me
  
  English Standard Version (ESV):
  
  Behold, I was brought forth in iniquity, and in sin did my mother conceive me.
  
  So there is NO teaching of Original Sin in this verse! The verse is concerning the sin of adultery; it does not mean the child is born with sin. In fact the verse does not make mention of Adam's sin.
  
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