How can every religion say that if you do not worship their God, you will go to hell?

Christians say that if people do not worship Jesus, they will go to hell, which is the everlasting fire. Hindus (Vaishnavas) say that if one does not worship Narayana, one goes to hell. I will ask one question. Till Vasco-da-Gama came to India, no Christian literature had reached India. Therefore the ancestors of Hindus were not aware of Jesus. Then for no fault of theirs, how could they go to the hell? The Lord gave His message to a small country at that time. Since the Lord is impartial, He should have given the same message to all the countries in this world. But He did not do so. This means you are forcing God to become partial. The same logic applies to Hindus also because when Narayana gave the Gita in India, the foreign countries were not blessed by such a preaching. Only after the visit of Vasco-da-Gama, the translation of the Gita reached foreign countries. Therefore the ancestors of foreigners cannot be blamed when they did not receive the Gita. In this situation there is no solution except this one solution. The only solution is that the same Lord came to different countries to give the same divine message in different languages. This is the best solution and brings the unity of religions.