Institutes of the Christian Religion (1559)
Book 2 - God the Redeemer
Chapter 2 - Man deprived of freedom of choice
Sections 18-21 - Spiritual discernment wholly lost until we are regenerated
Section 18 - the Limits of our understanding
Without grace, we only see the truth about God, our sin, and His salvation, as we see the landscape for an instant when lightning strikes. Then we are blind again.
Section 19 - Man's spiritual blindness shown from John 1:4-5
The darkness that is man has not understood the light.
Also John 1:13; Matt 16:17.
Section 20 - Man's knowledge of God is God's own work
"One cannot become wise in God's mysteries except by His gift."
"Man's mind can become spiritually wise only in so far as God illumines it."
Titus 3:5; Ps 36:9; 1 Cor 12:3; John 3:27; Deut 29:3-4; Jer 24:7; John 6:44; 1 Cor 2:14
Section 21 - Without the light of the Spirit, all is darkness
Positively, the Spirit must illumine our minds.
Eph 1:17-18; Ps 119:18; James 1:17; John 14:26; Acts 1:4.