"..There is no contradiction between true religion and science. When a religion is opposed to science it becomes mere superstition: that which is contrary to knowledge is ignorance.
How can a man believe to be a fact that which science has proved to be impossible? If he believes in spite of his reason, it is rather ignorant superstition than faith. The true principles of all religions are in conformity with the teachings of science.
The Unity of God is logical, and this idea is not antagonistic to the conclusions arrived at by scientific study.
All religions teach that we must do good, that we must be generous, sincere, truthful, law-abiding, and faithful; all this is reasonable, and logically the only way in which humanity can progress.
All religious laws conform to reason, and are suited to the people for whom they are framed, and for the age in which they are to be obeyed.
Religion has two main parts:
(1) The Spiritual.
(2) The Practical.
The spiritual part never changes. All the Manifestations of God and His Prophets have taught the same truths and given the same spiritual law. They all teach the one code of morality. There is no division in the truth. The Sun has sent forth many rays to illumine human intelligence, the light is always the same.
The practical part of religion deals with exterior forms and ceremonies, and with modes of punishment for certain offences. This is the material side of the law, and guides the customs and manners of the people.
In the time of Moses, there were ten crimes punishable by death. When Christ came this was changed; the old axiom 'an eye for an eye, and a tooth for a tooth' was converted into 'Love your enemies, do good to them that hate you', the stern old law being changed into one of love, mercy and forbearance!
In the former days the punishment for theft was the cutting off of the right hand; in our time this law could not be so applied. In this age, a man who curses his father is allowed to live, when formerly he would have been put to death. It is therefore evident that whilst the spiritual law never alters, the practical rules must change their application with the necessities of the time. The spiritual aspect of religion is the greater, the more important of the two, and this is the same for all time, it never changes! It is the same, yesterday, today, and for ever! 'As it was the beginning, is now, and ever shall be.'
Now, all questions of morality contained in the spiritual, immutable law of every religion are logically right. If religion were contrary to logical reason then it would cease to be a religion and be merely a tradition. Religion and science are the two wings upon which man's intelligence can soar into the heights, with which the human soul can progress.
It is not possible to fly with one wing alone! Should a man try to fly with the wing of religion alone he would quickly fall into the quagmire of superstition, whilst on the other hand, with the wing of science alone he would also make no progress, but fall into the despairing slough of materialism. All religions of the present day have fallen into superstitious practices, out of harmony alike with the true principles of the teaching they represent and with the scientific discoveries of the time. Many religious leaders have grown to think that the importance of religion lies mainly in the adherence to a collection of certain dogmas and the practice of rites and ceremonies! Those whose souls they profess to cure are taught to believe likewise, and these cling tenaciously to the outward forms, confusing them with the inward truth.
Now, these forms and rituals differ in the various churches and amongst the different sects, and even contradict one another; giving rise to discord, hatred, and disunion. The outcome of all this dissension is the belief of many cultured men that religion and science are contradictory terms, that religion needs no powers of reflection, and should in no wise be regulated by science, but must of necessity be opposed, the one to the other. The unfortunate effect of this is that science has drifted apart from religion, and religion has become a mere blind and more or less apathetic following of the precepts of certain religious teachers, who insist on their own favourite dogmas being accepted even when they are contrary to science. This is foolishness, for it is quite evident that science is the light, and, being so, religion truly so-called does not oppose knowledge.
We are familiar with the phrases 'Light and Darkness', 'Religion and Science'. But the religion which does not walk hand in hand with science is itself in the darkness of superstition and ignorance.
Much of the discord and disunion of the world is created by these man-made oppositions and contradictions. If religion were in harmony with science and they walked together, much of the hatred and bitterness now bringing misery to the human race would be at an end.
Consider what it is that singles man out from among created beings, and makes of him a creature apart. Is it not his reasoning power, his intelligence? Shall he not make use of these in his study of religion? I say unto you: weigh carefully in the balance of reason and science everything that is presented to you as religion. If it passes this test, then accept it, for it is truth! If, however, it does not so conform, then reject it, for it is ignorance!
Look around and see how the world of today is drowned in superstition and outward forms!
Some worship the product of their own imagination: they make for themselves an imaginary God and adore this, when the creation of their finite minds cannot be the Infinite Mighty Maker of all things visible and invisible! Others worship the sun or trees, also stones! In past ages there were those who adored the sea, the clouds, and even clay!
Today, men have grown into such adoring attachment to outward forms and ceremonies that they dispute over this point of ritual or that particular practice, until one hears on all sides of wearisome arguments and unrest. There are individuals who have weak intellects and their powers of reasoning have not developed, but the strength and power of religion must not be doubted because of the incapacity of these persons to understand.
A small child cannot comprehend the laws that govern nature, but this is on account of the immature intellect of that child; when he is grown older and has been educated he too will understand the everlasting truths. A child does not grasp the fact that the earth revolves round the sun, but, when his intelligence is awakened, the fact is clear and plain to him.
It is impossible for religion to be contrary to science, even though some intellects are too weak or too immature to understand truth.
God made religion and science to be the measure, as it were, of our understanding. Take heed that you neglect not such a wonderful power. Weigh all things in this balance.
To him who has the power of comprehension religion is like an open book, but how can it be possible for a man devoid of reason and intellectuality to understand the Divine Realities of God?
Put all your beliefs into harmony with science; there can be no opposition, for truth is one. When religion, shorn of its superstitions, traditions, and unintelligent dogmas, shows its conformity with science, then will there be a great unifying, cleansing force in the world which will sweep before it all wars, disagreements, discords and struggles - and then will mankind be united in the power of the Love of God."
('Abdu'l-Bahá: Paris Talks, Pages: 141-146)