God is Truth and Truth is God. This has been declared by all religions of the world. Truth stands by itself and it shines bright. However hard anyone may try to obscure it or hide it, Truth always reveals itself in the end. Truth always wins
Throughout ages Great Gurus, Sages and Avatars have taken birth to give knowledge and teach the Truth. Throughout the ages they have been persecuted. Always there will be groups of people who want to obscure knowledge and hide the truth. Christ was great teacher & guru and he gave knowledge to the people and proclaimed the truth about God. For doing so, he was nailed to the Cross. The ignorant and evil people of those days wanted to see if he was really Son of God and if he would die when he was nailed to the cross. Christ resurrected himself and showed the world that he was indeed Son of God and that he and his Father were one.
Unless man gets the ultimate knowledge & learns about the Supreme Truth and realises it, the purpose of his life is incomplete. Throughout ages God has sent his own spark in the form of Gurus to teach man about the Supreme Truth. The Guru has realized and experienced the Supreme Truth about God and he teaches this truth and gives this knowledge to mankind. Spiritual Practices are taught and the students follow them in order to reach the goal. Only disciplined and regular practice of the techniques and traditions taught by the Guru will help the student to reach the goal of Ultimate Truth and Knowledge.
Man works and earns wealth, power, position, influence. He collects possessions and things. He has family and friends. Yet he is always unhappy and feels that something is lacking in life. He keeps searching for happiness in form of more possessions, wealth and power. Until he knows and realises the Supreme Truth he will always be unhappy and incomplete.
