Knowing good and not doing it - is it a sin?

Good morning all!  God is good all the time, all the time God is good.  TOO BLESSED TO BE STRESSED!!
   Well, how has your week been thus far.  At Bible study last night pastor has been in James, chapter 4 verse 17 - which he noted how powerful this is: KJV ¹⁷ Therefore to him that knoweth to do good, and doeth it not, to him it is sin.     NIV  ¹⁷ If anyone, then, knows the good they ought to do and doesn’t do it, it is sin for them.
   I will quote from my commentaries as they do a much better job of expressing this than would I.  We tend to think that doing wrong is sin.  But James tells us that sin is also not doing right.   Huh?  What do you mean?  If I know that it is wrong to tell a lie and telling a lie is a sin; then, it can also be a sin to know the truth and not tell it.  This is knowing sinning just as lying.
   If I speak evil or gossip about someone - that is a sin.  Also, if I avoid that person when I know he or she needs my friendship - again, I have sinned.
   What are you saying.  I am saying the Holy Spirit guides us and we should be willing to follow the Spirits lead.  This comes straight from God.  So if God wants you to do a kind act, help, restore a relationship, then do it!!  By being obedient to God you will experience a renewed and refreshed vitality to your Christian faith.  
    Now go do the right thing.  Love you all.

In Christ's Love and Grace
  Johnny