So here we move on in our understanding of true spirituality in the Christian life. Basically it is a matter of our thoughts. The external is the expression, the results. Moral battles are not won in the external world first. They are always a result flowing naturally from a cause, and the cause is in the internal world of one’s thoughts. Inf fact, Jesus emphasized this with great force: You brood of snakes! How could evil men like you speak what is good and right? For whatever is in your heart determines what you say Matthew 12:34 NLT.
It is the internal that Jesus stresses. The internal comes before the external, and the internal produces the external. It is a matter of cause and effect.
In the Sermon on the Mount, Jesus deals with this, too. You have heard that our ancestors were told, ‘You must not murder. If you commit murder, you are subject to judgment.’ But I say, if you are even angry with someone, you are subject to judgment! Matthew 5:21-22 NLT.
Compare this with 1 John 3:15: Anyone who hates another brother or sister is really a murderer at heart. Now we have come a step further. The thought-world is still first, but here we are told something else. In relation to morals, the thought is the thing. Hate does not just lead to murder; morally, it is murder. Now we are stressing morally, the hate is the murder.
So far we have taken three steps: first, the internal is first; second, the internal causes the external; third, morally, the internal is central.
Thoughts developed or used directly from the work of Schaeffer, Francis. True Spirituality . Tyndale House Publishers, Inc