Rationalism

The word rationalism does not appear in scripture.
However the word carnal does.

So, when we encounter the word carnal we can rightfully substitute rational.
For to be carnally minded is death; but to be spiritually minded is life and peace.
Spiritual Minded is thinking, meditating, talking and acting from the Word by the Holy Spirit.
Carnal Minded is the opposite, It is disconnected from the Word and the Holy Spirit.     It is of the flesh.

Because the carnal mind is enmity against the Lord: for it is not subject to the law of the Lord, neither indeed can be. Translated from KJV
The Lord is a Spirit. He does not relate to the animalistic tendencies of man because that mindest cannot grasp the value of His laws and so cannot live in them.

(For the weapons of our warfare are not carnal, but mighty through the Lord to the pulling down of strong holds;) Translated from KJV
Spiritual Warfare is the undercurrent of all the psychological, emotional, moral, political, social and economic turmoil in the world.
No one can escape this warfare.     There is no possibility of being neutral.     The warfare comes to every person, every family, every church, every community, every state and every nation
Since Spiritual Warfare is unavoidable, we must first choose sides , secondly prepare for battle and thirdly go forth into the battle .
In order to fight the good fight of faith we must put on the whole armour of the Lord .
Once we are properly fitted for defense and protection we are to take up the Sword Of The Spirit - the Word Of The Lord .
The Word Of The Lord is our offensive weapon.
When wielded in faith under the inspiration of the Holy Spirit it will pull down any stronghold that the enemy sets up.
Without the Word Of The Lord we cannot defeat the enemy.     But when we go on offense with it, we will knock down the Gates Of Hell .

Now, it is a fact that our Creator gave us the power of rational thinking. But it is also a fact that that power was intended to function within our Creator's knowledge.

When Adam chose to explore knowledge outside of the Creator's he gained some knowledge but lost a wealth of knowledge - specifically knowledge of the Truth.

Partial Truth was revealed to righteous men throughout the first four thousand years of our sojourn on earth. But absolute, pure Truth came to mankind In Christ Jesus.

Despite the gift of Light and Truth by Christ Jesus, man was under the attack of Satan whose primary goal is to steal the Truth.

The tension between Revelation Knowledge and rationalism is palpable. Even the devoutest of believers struggle with their tendency to think things through rather than trusting the Word Of The Lord.

As a result, Christianity has always been less than what our Lord had in mind for us.

Because of the often poor example and teaching regarding the Truth, those with strong tendencies toward rationalism would move completely away from Christianity.

The partial Truth demonstrated by the church is better than no Truth at all.

But because of the lingering positive effects, even of partial Truth, those who were prone to rationalism assumed that their starting point was 'natural'.

This is the major fallacy of rationalism.

Accordingly, as society has moved further and further away from Revelation Knowledge into rationalism we see the downward spiral of humanity.

The positive effects of partial Truth have dissipated over generations as the amount of Truth in our education (family, church and schools) decreased.

Rationalism is circular logic. It has no foundation except invalid assumptions and has no future except nihilism.

Satan wins in the life of an individual who worships rationalism.

Satan wins in the life of a society which worships rationalism.
The thief comes not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly.
The thief is Satan who is the inspiration for all the evil in the world.
Whereas the 'I' is Jesus who offers us Eternal Life and Abundant Life.
This verse is a powerful statement contrasting the nature of the enemy with the nature of our Lord Jesus Christ.
Note that the enemy takes by force what is ours, while we must appropriate by faith what is ours in Christ Jesus.
The appropriation is not a 'one and done' thing.     Rather, it is an ongoing process throughout our lives on this earth.
Jesus has given us His life in giving us His Holy Spirit who is in every believer who has asked to be filled.     We aught to invoke His life into every aspect of our walk in the earth.