Tozer gets rather deep in this week's chapter. It is difficult to get through without a broader reading of Tozer's materials in books such as The Knowledge of the Holy, The Pursuit of God, and God's Pursuit of Man to name but a few. He mentions "three degrees of knowledge open to Christians."
1. "The first is the common knowledge shared with all persons, namely the data furnished by the senses and by reason operating upon such data."
2. "The second is the knowledge received by faith. It consists of all data given by divine revelation and received by the believing mind without proof.
3. "The third kind of knowledge is that given by direct spiritual experience...It has nothing to do with the senses and so it is not physical or natural data It has nothing to do with ethics or doctrine so it is not moral or theological knowledge."
Now before we get too far into the weeds some background on this type of discussion is in order. Traditionally, Reformed Christian theology has put forth two types of Revelation (that is means by which God reveals Himself who is Truth)
1. The first is General Revelation - information about God which is discerned through nature and reason -
The heavens declare the glory of God,
and the sky above proclaims his handiwork.
Day to day pours out speech,
and night to night reveals knowledge. [ Psalm 19:1-2]
The statutes of the Lord are trustworthy, making wise the simple.
The commands of the Lord are radiant, giving light to the eyes.
The decrees of the Lord are firm, and all of them are righteous.