Divine in Origin but Human in its actual nature

Religion belongs to the higher mind of humanity. It is the effort of man’s higher mind to approach, as far as lies in its power, something beyond it, something to which humanity gives the name God or Spirit or Truth or Faith or Knowledge or the Infinite, some kind of Absolute, which the human mind cannot reach and yet tries to reach. Religion may be divine in its ultimate origin; in its actual nature it is not divine but human. In truth we should speak rather of religions than of religion; for the religions made by man are many. These different religions, even when they had not the same origin, have most of them been made in the same way.
[CWM2, 3:76]

How can Religion help in my spiritual growth?

The articles and dogmas of a religion are mind-made things and, if you cling to them and shut yourself up in a code of life made out for you, you do not know and cannot know the truth of the Spirit that lies beyond all codes and dogmas, wide and large and free. When you stop at a religious creed and tie yourself in it, taking it for the only truth in the world, you stop the advance and widening of your inner soul. But if you look at religion from another angle, it need not always be an obstacle to all men. If you regard it as one of the higher activities of humanity and if you can see in it the aspirations of man without ignoring the imperfection of all man-made things, it may well be a kind of help for you to approach the spiritual life. Taking it up in a serious and earnest spirit, you can try to find out what truth is there, what aspiration lies hidden in it, what divine inspiration has undergone transformation and deformation here by the human mind and a human organisation, and with an appropriate mental stand you can get religion even as it is to throw some light on your way and to lend some support to your spiritual endeavour.
 In all religions we find invariably a certain number of people who possess a great emotional capacity and are full of a real and ardent aspiration, but have a very simple mind and do not feel the need of approaching the Divine through knowledge. For such natures religion has a use and it is even necessary for them; for, through external forms, like the ceremonies of the Church, it offers a kind of support and help to their inner spiritual aspiration. In every religion there are some who have evolved a high spiritual life. But it is not the religion that gave them their spirituality; it is they who have put their spirituality into the religion.
[CWM2, 3:78]

Religion has to be a free choice from within

If you want to appraise the real value of the religion in which you are born or brought up or to have a correct perspective of the country or society to which you belong by birth, if you want to find out how relative a thing the particular environment is into which you happened to be thrown and confined, you have only to go round the earth and see that what you think good is looked upon as bad elsewhere and what is considered as bad in one place is welcomed as good in another. All countries and all religions are built up out of a mass of traditions. In all of them you will meet saints and heroes and great and mighty personalities as well as small and wicked people. You will then perceive what a mockery it is to say, “Because I am brought up in this religion, therefore it is the only true religion; because I am born in this country, therefore it is the best of all countries.” One might as well make the same claim for his family, “Because I come of this family that has lived in the same place for so many years or so many centuries, therefore I am bound by its traditions; they alone are the ideal.”
Things have an inner value and become real to you only when you have acquired them by the exercise of your free choice, not when they have been imposed upon you. If you want to be sure of your religion, you must choose it; if you want to be sure of your country, you must choose it; if you want to be sure of your family, even that you must choose. If you accept without question what has been given you by Chance, you can never be sure whether it is good or bad for you, whether it is the true thing for your life. Step back from all that forms your natural environment or inheritance, made up and forced upon you by Nature’s blind mechanical process; draw within and look quietly and dispassionately at things. Appraise them, choose freely. Then you can say with an inner truth, “This is my family, this my country, this my religion.”
[CWM2, 3:80-81]

Limitations of Religion

The strength and greatness of a religion is adjudged by men according to the number of those that follow it, although the real greatness is not there. The greatness of spiritual truth is not in numbers. I knew the head of a new religion, the son of its founder, and heard him say once that such and such a religion took so many hundreds of years to be built up, and such another so many hundreds of years, but they within fifty years had already over four million followers. “And so you see”, he added, “what a great religion is ours!” Religions may reckon their greatness by the number of their believers, but Truth would still be Truth if it had not even a single follower. The average man is drawn towards those who make great pretensions; he does not go where Truth is quietly manifesting. Those who make great pretensions need to proclaim loudly and to advertise; for otherwise they would not attract great numbers of people. The work that is done with no care for what people think of it is not so well known, does not so easily draw multitudes. But Truth requires no advertisement; it does not hide itself but it does not proclaim itself either. It is content to manifest, regardless of results, not seeking approbation or shunning disapprobation, not attracted or troubled by the world’s acceptance or denial.
[CWM2, 3:83]
That is why religions are always mistaken—always—because they want to standardise the expression of an experience and impose it on everyone as an irrefutable truth. The experience was true, complete in itself, convincing—for the one who had it. The formulation he made of it was excellent—for himself. But to want to impose it on others is a fundamental error which has altogether disastrous consequences, always, which always leads far, very far from the Truth.
That is why all the religions, however beautiful they may be, have always led man to the worst excesses. All the crimes, the horrors perpetrated in the name of religion are among the darkest stains on human history, and simply because of this little initial error: wanting what is true for one individual to be true for the mass or collectivity.
[CWM2, 9:406-07]

Beyond Organised Religion

All religions are partial approximations of the one sole Truth that is far above them.
[CWM2, 15:28]
Each religion has helped mankind. Paganism increased in man the light of beauty, the largeness and height of his life, his aim at a many-sided perfection; Christianity gave him some vision of divine love and charity; Buddhism has shown him a noble way to be wiser, gentler, purer; Judaism and Islam how to be religiously faithful in action and zealously devoted to God; Hinduism has opened to him the largest and profoundest spiritual possibilities. A great thing would be done if all these God-visions could embrace and cast themselves into each other; but intellectual dogma and cult-egoism stand in the way.
All religions have saved a number of souls, but none yet has been able to spiritualise mankind. For that there is needed not cult and creed, but a sustained and all-comprehending effort at spiritual self-evolution.
[SABCL, 16:394]

Towards a Spiritual Religion of Humanity

A spiritual religion of humanity is the hope of the future. By this is not meant what is ordinarily called a universal religion, a system, a thing of creed and intellectual belief and dogma and outward rite. Mankind has tried unity by that means; it has failed and deserved to fail, because there can be no universal religious system, one in mental creed and vital form. The inner spirit is
indeed one, but more than any other the spiritual life insists on freedom and variation in its self-expression and means of development. A religion of humanity means the growing realisation that there is a secret Spirit, a divine Reality, in which we are all one, that humanity is its highest present vehicle on earth, that the human race and the human being are the means by which it will progressively reveal itself here. It implies a growing attempt to live out this knowledge and bring about a kingdom of this divine Spirit upon earth. By its growth within us oneness with our fellow-men will become the leading principle of all our life, not merely a principle of cooperation but a deeper brotherhood, a real and an inner sense of unity and equality and a common life. There must be the realisation by the individual that only in the life of his fellow-men is his own life complete. There must be the realisation by the race that only on the free and full life of the individual can its own perfection and permanent happiness be founded. There must be too a discipline and a way of salvation in accordance with this religion, that is to say, a means by which it can be developed by each man within himself, so that it may be developed in the life of the race.
A spiritual oneness which would create a psychological oneness not dependent upon any intellectual or outward uniformity and compel a oneness of life not bound up with its mechanical means of unification, but ready always to enrich its secure unity by a free inner variation and a freely varied outer self-expression, this would be the basis for a higher type of human existence.