Here's the Doctor on "Heavenly Things" (John 3:8) in chapter 12 of Experiencing the New Birth:
"What is your view and mine of the Christian life? Far too often it is just this: 'Oh yes, I believed in Jesus Christ at conversion. I made a decision and accepted him.' You have relied upon that. You have stopped doing certain things, and you begin to do others, and you have it all nice and complete. You do your duties, and you may be active in work, and there you are. You are self-content, and you think that is Christianity. But, my dear friends, is it? Have we received his fullness and grace, ever expanding until we know something of the fullness of God himself? I feel this has been one of the great troubles perhaps in the present century—and I am talking to evangelical people in particular. I feel we have made the gospel something small, sometimes even something glib, something that we can handle, so that we are afraid of yielding ourselves to the possibilities that are put before us in the New Testament Scriptures. Now this is something that is quite fatal, this limiting of the gospel to the level of our understanding and comprehension. There is a danger that many today are even interpreting the Scriptures in terms of their little experience instead of judging their experience by the teaching of the Scriptures."
--Martyn Lloyd-Jones, Experiencing the New Birth (Crossway, 2015)