Occasionally we hear an opinion that the Sanatan Dharma is in decline, since it hasn’t spread across the globe as widely as so-called world religions of Christianity and Islam.
A fundamental fallacy in this claim is to draw any comparison between Sanatan Dharma and these two religions, which now have largely become belief systems where the adherents hardly practice anything of what is preached, except perhaps a few. This is because these religions are forces imposed upon people by fear and favour, silver and sword. Such methods succeed outwardly in winning adherents quickly but are destined to collapse in the absence of the yoga and its living representatives. Man cannot live content forever with a belief system especially in our age. He wants to experience and know and become. That option is only open for the group where the yoga is kept alive.
Christianity closed this door when the Church and the Pope replaced Christ, the Book replaced the living Veda in the heart with which Christ communed and a crystallized sophisticated institutional machinery replaced the ministry of Christ. Contrary to what you say there are more and more people getting disgruntled with belief systems that often sound too archaic in the absence of Yogis who can reveal the true significance of the symbols. As to present day Islam the lesser said the better. Here the yoga is not only lost but lost beyond retrieval. Its mystic element was destroyed with the death of the Sufis and the institution built around the supposed throne of God was appeased with the blood of innocents.
The Sanatan Dharma, on the other hand grew organically as life itself, rediscovering and reinventing itself through the difficulties and challenges. It never spread much because it did not believe in artificial ways of conversion and pedaling truth in the shining garb of a lie or selling a profound wisdom in neat and well packaged formula as a product with catchy tagline such as ‘believe and thou shalt be saved in another world regardless of your deeds and motives’.
True Christianity and Islam spread like wild fire through these means but what is left of these in real terms (and not in terms of numbers) are empty churches, stone-hearted often cruel clergies and a lot of hypocrisy. Well, if you count by the surname and swearing by the holy book the numbers are there. But is that truly what matters? The Sun shines alone and is incomparable to any number of lamps in the night. It needs nobody’s acknowledgement or prayer and supplication or approval. It does what it must do regardless of our beliefs and non-beliefs to uphold the Dharma. This is Sanatan Dharma which needs neither numbers not conversions not even a formal belief in God. In fact, even if there was not a single follower or even if the earth and humanity were destroyed through successive pralayas, Sanatan Dharma would re-emerge. It is so because it has not been born or originated from any man or woman or saint or sage or even Avatar but exists in the very stuff of creation as the Supreme Origin as the compelling impulsion in it. That is why Sri Krishna says that the Sanatan Dharma was first given by the Sun God (Creator), Vivaswan, child of the Divine Mother Aditi and from there to Ikshavaku king of the Solar Dynasty. He also reveals that it is eclipsed from time to time not because its followers decrease but because humanity, believers and non-believers and all the rest, deviate from Dharma, the Divine Will that is dynamic in creation as the operating Intelligence or Conscious Force. To one who understands Sanatan Dharma, a true Christian with genuine bhakti for Christ is a ‘Sanatani’. Thinkers and Scientists of eminence such as Emerson, Schrodinger and Muslims like Abdul Kalam drew their inspiration from Sanatan Dharma without needing to change their name or practice any outer rituals. How would such a vast and catholic approach to Truth perish? Can Truth perish? Can life perish? Even if Earth were destroyed life would exist elsewhere, in fact everywhere. Even if none believed in Truth it would exist as a self-existent Reality.
Such is the power of Sanatan Dharma and so much more than volumes of books can convey, let alone a brief letter. That is why there are countless sages and saints and yogis and scriptures in Sanatan Dharma because it is infinite and inexhaustible. Yes it does reveal that man in his deepest Self is one with God and it is our business to realise it and remolds our life rather than follow one book and one prophet.