“Tapah-svadhyayesvara-pranidhanani kriya-yogah” –Kriya-yoga, the path of action, consists of self-discipline, study, and dedication to the Lord. Yoga Sutra 2.1
The fifth niyama Ishvarapranidhana is surrender to the Lord, the Divine. While it is not pointing out a specific religious identity, it is merely the idea that one must surrender to the Divine within ourselves, as well as within and throughout the world. It is considered the last step of Bhakti where the mind becomes completely dedicated to Brahman. Swami Jnaneshvara explains it as thus:
The emphasis of Ishvara Pranidhana practice is the release or surrender that is done in a sincere, dedicated, or devotional attitude.
After introspection and letting go of perceptions and assumptions, the yogi can focus on the true state of their mind, as well as the world around them. This can only be done through letting go of all previous attachments and letting our minds release the discoloration of our thoughts. Surrender being a powerful word here, giving oneself completely with no expectations will lead the yogi into a deeper practice, leading to samadhi. The yamas and niyamas are very much part of the path of Kriya yoga, that path of action. By taking action, by taking these steps one can move deeper into their meditation practice. It is considered the last step of the niyamas, and it is considered one of the best states of mind because the yogi has surrendered and become one with Brahman.
When I teach a class, I always instruct the students to surrender; surrender completely to the breath, the asana, the meditation, the practice. In my opinion, the complete surrender to yourself to your practice is the hardest thing, as life has many distractions and stressors that will pressure a person to distance themselves. Concentrating the breath, body, and mind, a student can delve into themselves, which takes courage. Many do not like to look too closely to themselves, and by after the yamans and niyamas the Self becomes disciplined, focused, and surrenders to the practice.