Samadhi is the journey from individual to collective consciousness. The steps of Samadhi are the steps towards reaching the collective consciousness. In meditation, the more we radiate love, compassion, peace, harmony and tranquility, the more is our contribution towards the collective consciousness. The more we positively contribute towards the collective consciousness the more is our progress in Samadhi.
Spiritual principles, if true, are true for everyone. That is the yardstick that validates their authenticity. Authentic spiritual ideas also have the universal power to heal. Healing is the building block of both individual and collective spiritual evolution.