Holy, Holy Holy! (Isa. 6:3, Rev. 4:8)
I would have to say among the many things taught in Reformed circles, the truth of the Holiness of God comes forth loud and clear (AMEN FOR THAT!).  This truth that God is HOLY is something I “knew about” for over 34 years, but it is more real to me now (since becoming Reformed) than at any other time in my walk.  In part, God used R.C. Sproul’s book “The Holiness of God” and his DVD series by the same name to help me under

Loving the PURE Word of God!!! ALL OF IT!
As a minister, I know how easy it is to preach your “favorite” subject.  Usually your favorite subject is a subject that has changed your life.  I even see this in Reformed churches.  They seem to talk a lot about “God’s Sovereignty,” “Election,” “Grace,” etc.   I think you get the point.   I am tempted to do the same,  all 3 of the subjects I listed have changed my life: therefore, I speak of them often.  BUT we need to be careful  not to go to such an extreme that we NEVER speak on anything but