Reaching state of self realization is the ultimate goal of human life on mother earth. Mahavira, Gautama Buddha did so and so did Jesus Christ and Prophet Mohammed. Even Sri Ramakrishna Paramhansa and Maharshi Ramana succeeded in gaining self realization in their lifetime.
Self realization is reached indulging in spirituality as detailed in Bhagavad Gita. There is no other method or a shortcut method of reaching state of self realization.
People who did not believe in Bhagavad Gita, the world of God and also souls atmans were totally incompetent to indulge in spirituality to reach state of self realization.
Unless we had 100% faith in God and his system, if we can indulge in truthfulness 100%, if we had the capability to indulge in absolute celibacy for a minimum period of 12 years in continuation, there is no point indulging in spirituality to reach state of self realization.
Prime reason why in last about 150 years amongst 7000 million people existing world over only Sri Ramakrishna Paramhansa and Ramana Maharshi succeeded in reaching state of self realization.
We may or we may not belong to fold of Hinduism, it does not matter. Even while following ones religion, faith or belief one can indulge in spirituality detailed in Bhagavad Gita to reach cosmic end of life, state of self realization! For following Bhagavad Gita one need not convert to Hinduism. Teachings contained in Bhagavad Gita were universal in nature, applicable to all.
The spirit, soul atman existing in heart manifests human form to remove dross impurities within. Indulging in spirituality detailed in Bhagavad Gita the moment human beings negate karma to zero, the cosmic journey of soul atman, spirit finally ends forever.
In absence of dross impurities within a pure soul atman need not manifest a human body again. The need to manifest a human body any further now ceases to exist.
Indulging in spirituality and reaching state of self realization is the most pleasant experience not only for human form but soul atman within.
However God Almighty endowed all human beings with free will, power of discrimination exercising which we can decide our goal of life. We can cover the spiritual journey detailed in Bhagavad Gita in present life time or leave it for future manifestations by our soul atman.