No matter how many years, decades of centuries pass, not a single individual belonging to Christianity or Islamic Dharma would succeed reaching state of self realization. The reason is apparent! Both Jesus Christ and Prophet Mohammed succeeded in reaching state of enlightenment, self realization by indulgence in teachings contained in Bhagavad Gita and also Upanishads (independent spiritual treatises).
Both Bhagavad Gita and 11 principal Upanishads form core of spirituality indulging in which any human being world over can easily reach state of enlightenment, self realization, god realization. There was nothing more pure than teachings of spirituality contained in Bhagavad Gita.
I was born in Jainism religion but around six years of age I realized that it was easier to indulge in teachings of Lord Krishna than Jainism scriptures. I had so many queries within. Whenever I asked elders in the family and outside about queries relating to Jainism scriptures, all remained mum. None had the correct answer.
I diverted myself to teachings of Lord Krishna in Bhagavad Gita. Even though there was none available to guide me in respect of Bhagavad Gita but many stories about Lord Krishna did the rounds in my house. As I was apt in the art of contemplation (chintan), I could easily connect to teachings of Lord Krishna in Bhagavad Gita.
To reach state of self realization apart from teachings of Lord Krishna, the doctrine of Anekantavada of Jainism came to my rescue. I was deeply perplexed and unable to understand something relating to spirituality. The moment I indulged in teachings of Mahavira relating to Anekantavada, I immediately reached state of Nirvikalpa samadhi (absolute nothingness). Thereafter it was never looking back.
In my spiritual quest I never discarded any religion or any guru belonging to any religion. If someone knew more than me, in that particular moment one was my guru. Whatever little one had to teach I accepted it with folded hands. In my journey of spirituality I learnt many things from various followers of Christianity and also Islamic Dharma.
As one who succeeded in reaching state of self realization, I can emphatically say to reach state of self realization one must indulge in teachings of Bhagavad Gita only. No other scripture is necessitated apart from teachings contained in Bhagavad Gita.
For indulgence in Bhagavad Gita one need not convert to Hinduism religion. Even while following ones religion, faith or belief one can seriously indulge in teachings of Lord Krishna in Bhagavad Gita to reach state of self realization, god realization.