Rationalism is a reliance upon reason in order to determine what is true. Rationalism is reason (what man thinks) and places a low value (or no value) on divine revelation (what God has said in His Word, the Bible). The emphasis is upon reason rather than revelation. (Middletown bible church)
The Bible says, “Thy word is truth”… Rationalism says, “Thy mind is truth”…
Prov 3:5 Trust in the Lord with all thine heart; and lean not unto thine own understanding.
“Rationalism is an epistemological position which believes that knowledge starts with what can be known by pure reason. (Epistemology is the study of what can be known and how.) The main premises of rationalism are a priorism, objectivism, foundationalism, and exclusivism. A priorism is the epistemological position that knowledge can be obtained a priori, that is prior to experience. This contrasts with empiricism, which is the epistemological position that knowledge can be obtained a posteriori, meaning after experience. Objectivism refers to the belief that there exists an objective reality that is knowable. Foundationalism refers to the belief that first principles exist which can be built upon. Exclusivism refers to the belief that two fundamentally opposite positions cannot both be true (Geisler 633-634).
Three of the important philosophers for the rationalist movement were Rene Descartes (1596-1650), Gottfried Wilhelm Leibniz (1646-1716), and Baruch Spinoza (1632-1677). It is interesting to note that Descartes and Leibniz were both devout Christians who were motivated to do their work for the glory of God and furtherance of Christianity.
The major project of Rene Descartes was to doubt everything and start his system of thought from an undoubtable first proposition. The result of Descartes’ work led him to the famous maxim “cogito ergo sum” or “I think therefore I am.” Through this principle maxim Descartes was able to build an entire system of philosophical thought that laid the foundation for the rationalist thinkers who came after him.
[1 Cor 8:1 Now as touching things offered unto idols, we know that we all have knowledge. Knowledge puffeth up, but charity edifieth. 2 And if any man think that he knoweth anything, he knoweth nothing yet as he ought to know.]
Leibniz influenced the rationalists through his heavy emphasis on rational proof for the existence of God. His system of philosophy relied heavily upon a particular rationalistic argument for the existence of God called “the principle of sufficient reason” (Blackburn 215-216). This is the principle that everything must have an adequate reason for existence (367). Leibniz was also an advocate of natural theology. This means that he believed one could come to conclusions regarding the attributes of the creator of the universe through observation of what has been made. This can be seen in Part II of his Discourse on Metaphysics; “…it is in reflecting upon the works that we are able to discover the one who wrought.” Natural theology would later become a major tenet of deism.
Spinoza was heavily influenced by the Jewish philosophers Moses Maimonides and Philo, as well as by Descartes (Geisler 709), and he met Leibniz on at least one occasion (Blackburn 215-216). Spinoza was a pantheist, believing that God and the universe were one and the same (Geisler 710, Audi 870). He believed in rational proof for the existence of God and was a strict rationalist.”
(apologetics.com)
(The following is from Christian-rationalism.org)
Christian Rationalism’s fundamental principles encompass concepts as old as the Universe and life, as well as a sound pattern of behaviour for those who wish to follow it. This behaviour leads man to the knowledge of himself as Force and Matter. It shows that in every manifestation of life there is a flicker of Intelligence, which, like in ourselves, is part of Total Life. Thus we learn that we are but small torches of life, still very blunt, part of an immense flash of lightning driving forward the Cosmos – which is Universal Intelligent Life.
In this regard there is no better person to explain why Christian Rationalism is a science than Dr. Antonio Pinheiro Guedes (brazilian scientist and physician). In his book Spiritualistic Science wrote the following:
“Science is the knowledge of things, facts and phenomena in themselves, in their nature and in the relationship between them and everything that surrounds them. Such knowledge can only be obtained through systematic study, close observation and detailed analysis. Consequently, science is the product of our intelligence, the result of our work. It aims at a goal, it fulfils a need of our spirit. The spirit ceaselessly feels the need to investigate. It is eager for knowledge. It always wants light, more light.
[1 Cor 3:18 Let no man deceive himself. If any man among you seemeth to be wise in this world, let him become a fool, that he may be wise. 19 For the wisdom of this world is foolishness with God. For it is written, He taketh the wise in their own craftiness. 20 And again, The Lord knoweth the thoughts of the wise, that they are vain.]
The purpose of Spiritualistic Science (which is the case of Christian Rationalism) is to enlighten us about other worlds and life after death, to prove the existence of the soul, its preexistence and survival to the body.
The facts which ‘Spiritualistic Science’ deals with are not supernatural, not even extraordinary. They simply escape the observation of those who do not know how to see. They are natural, like everything else in the Universe. They are common, ordinary and even frequent. But to see them, learn to notice them and recognise them whenever and wherever they are present, it was necessary to discover an instrument capable of recording them, making them evident and obvious. Such instrument is the medium. [The medium is simply a channel between the spiritual world and us.] Once the instrument was found and its capabilities studied, facts began to be observed. First spontaneous facts, later induced ones were observed with the purpose in mind of recognising the nature of the cause which produced such phenomena. As a result of spiritualistic studies, the immortality of the soul is established on principles determined by perfectly irrefutable evidence. The reincarnation of the human spirit, consisting of successive existences or multiple bodily lives of a conscious individual, is a law to which all spirits are subject and is an essential condition for its advancement.
There is a Philosophical School called “Rationalism” that should not be confused with “Christian Rationalism”. The former is of materialistic nature while the latter is eminently spiritualistic. Therefore they are diametrically opposed.
Christian Rationalism is not associated with and is not similar to any other religion or doctrine on Earth. It is unique and consists of only one code and only one discipline. This a spiritualistic philosophy that explains in a simple and rational manner, who are we, where did we come from and where are we going to.
Thousands of years ago great men driven by ideals of reform tried with their teachings to debrutalize humanity. Such men like Jesus, Budda, Confucius and Mohammed taught similar spiritual principles, however besides not being understood, ended up deified by the illiterate masses. Once the idea of divinization took hold, the respective religions were created, each preaching a different form of speculative worship, and the followers of each flocked together. Jesus Christ and all the others were just men, remarkable men in fact, but nevertheless, human beings like all of us, without any divine affiliations. The person known as Jesus was just a man, though one of the the greatest men that ever existed on Earth! (Christian-rationalism.org)\
1 Cor 2:14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned. 15 But he that is spiritual judgeth all things, yet he himself is judged of no man. 16 For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ.
“One thing is certain about “Christian Rationalism”—there is nothing Christian about it. Christian Rationalism claims to be a science and a philosophy, not a religion, and makes no pretense to be “Christian” at all in the sense of believing in and following Christ, worshipping Him, and obeying His commands. Like all false religions, Christian Rationalism rejects the deity of Christ, the Bible as the Word of God, and salvation by faith in Christ alone.
According to its adherents, Christian Rationalism deals with physical and psychic phenomena, philosophical and psychological issues, reincarnation, “incorporeal life,” space and the universe, the power of thought, evolution, gods and religions, force and matter, the aura, ethics, family and children.
The basic beliefs of the Christian Rationalists are contrary to Scripture, beginning with their concept of God as a “universal spiritual force, or a universal intelligence,” not a Person. CR adherents see God as made up of “billions and billions of intelligent spiritual particles,” of which man is part. That means that each one of us is a particle of that universal force which is God. This philosophy is rampant among New Age cults and false religions.”
(gotquestions.org)
Isa 55:7 Let the wicked forsake his way, and the unrighteous man his thoughts: and let him return unto the Lord, and he will have mercy upon him; and to our God, for he will abundantly pardon. 8 For my thoughts are not your thoughts, neither are your ways my ways, saith the Lord. 9 For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts.
Some have argued that the [Theistic Rationalism] properly describes the beliefs of some the Founding Fathers of the United States, including George Washington, John Adams, Benjamin Franklin, James Wilson, and Thomas Jefferson. Theistic rationalists believe that God plays an active role in human life, rendering prayer effective. They accept parts of the Bible as divinely inspired, using reason as their criterion for what to accept or reject. Their belief that God intervenes in human affairs and their approving attitude toward parts of the Bible distinguish Theistic Rationalists from Diests. (Wikipedia)