Question: Is there any verse in the Bible that says anything about the split between conscious and unconscious mind?
The Bible is filled with distinctions between conscious and subconscious. However a clear demarcation in the original languages is not always clear as the those precise terms were not used. In English we often refer to our subconscious with other words and it is the same way in Biblical Hebrew and Greek
For example εβουλομην often means 'consciously purposed' as here:
15 Και ταυτη τη πεποιθησει εβουλομην προς υμας ελθειν προτερον ινα δευτεραν χαριν
Because I was confident of this, I wanted to visit you first so that you might benefit twice. (NIV 2 Corinthians 1:15)
On the converse θελω often means 'subconscious desires' as in this verse:
19 ου γαρ ο θελω ποιω αγαθον αλλ ο ου θελω κακον τουτο
For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing. (NIV Romans 7:19)
According to the TDNT by Gerhard Kittel:
The one finds in θέλειν impulsive and unconscious desire, and in βούλεσθαι rational and conscious.
However just as in English these words tend to overlap and can be substitutes for each other. Phrases like 'having a desire', 'seeking', 'wanting' or 'purposing' or 'being ready or inclined' may have to be assigned to the conscious, subconscious, both, or neither, depending on the context.
2 Peter 2:12 talks about unrighteous men who indulge the flesh. The verse describes them as "creatures of instinct" and "unreasoning animals".
It seems significant that they are described as being moved by "instinct" rather than "reason".
This seems to indicate that it is error to be led by the "unconscious mind" at the expense of the "conscious mind".
I'm not sure "walking" should be classified as "unconscious", though; indeed, if it were, you may walk into traffic without thinking, as a sleep-walker might. ;p
The verse that stands out for me here is Psalm 32:9:
Do not be like the horse or the mule, which have no understanding but must be controlled by bit and bridle or they will not come to you.
I read it as: "don't just go on autopilot or on habit, following the crowd. God gave you a brain, use it!"
Many times in the bible it is stated about the blind and deaf ( this is the unconscious, those that can hear the words preached, but not have any sense of what those words mean)...all those with ears listen ( well everyone has ears right?) But its the person with consciousness in christ (born again) that can truly hear, see and interpet the bible and make sense of Jesus's parables, threw the gift of the holy spirit.
Matthew 13:15 For this people's heart has grown dull, and with their ears they can barely hear, and their eyes they have closed, lest they should see with their eyes and hear with their ears and understand with their heart and turn, and I would heal them.
Deuteronomy 29:4 But to this day the Lord has not given you a heart to understand or eyes to see or ears to hear.
( enlightened or made aware of or conscious of )
For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt.