The only truth in the universe according to indian Philosophy is the Atma (Soul, Self, Universe Energy, Consciousness or God) that is the sole reality. Everything else is perishable. Innumerable changes happen in nature, but the Atma always remains constant. It neither has a beginning, nor an end. It is immortal.
The Atma (Soul) existed before the concept of any other form of God. Contemplation and meditation on the Atma even for a moment can lead us towards the experience that we and the Atma other same self realization. This is the same state we see to achieve by the practice of The Atma (Soul) is present in one and all and resides in our heart. The easiest and the most effective way to attain the state of Yoga is to meditate on the Atma in our heart. Since the Atma is formless without any physical properties. It is easier if we meditate on form. The most effective being that of the Sadguru one who is constantly absorb in Atma and constant meditation on his form in once heart we surely lead to self-realization.
The Atma (Soul) is omnipotent, omnipresent and omniscient. It does not belong to any particular country, religion or cast. Every human being can attain God by means of worship and contemplation on the Atma. Jesus Christ, Prophet Mohammed, Shri Krishna, Guru Nanak, Lord Mahavir, Prophet Zarathustra, Lord Buddha and other saints throughout history all attained self-realization becoming one with God, by constant meditation and contemplation on Atma.