Hinduism's greatest insight may be its most practical: different people need different paths to the divine.
The philosopher needs Jnana Yoga — the path of knowledge, as taught in the Upanishads. The devotee needs Bhakti Yoga — the path of love, as taught by the poet-saints. The activist needs Karma Yoga — the path of selfless action, as taught in the Gita. The contemplative needs Raja Yoga — the path of meditation, as systematized by Patanjali.
The Bhakti movement (roughly 6th-17th centuries CE) was Hinduism's great democratization. Poet-saints like Kabir, Mirabai, Tukaram, and Tulsidas wrote in local languages (not Sanskrit), rejected caste hierarchy, and declared that God was available to anyone with a loving heart.
Kabir (c. 1440-1518) is perhaps the most radical of all. Born a Muslim weaver in Varanasi, he drew equally on Hindu and Islamic mysticism, mocking the empty rituals of both traditions. His poems are sung across India today — by Hindus, Muslims, and Sikhs alike.
Meanwhile, Patanjali's Yoga Sutras (c. 200 BCE-200 CE) systematized the inner science of meditation into eight limbs — from ethical conduct to breathwork to the deepest states of absorption (samadhi). What the West calls "yoga" (physical postures) is just one of these eight limbs.