Is science the only method that can prove the existence of God?

entertain for a second the notion that God does exist (for argument sake). do you think He would make His existence known only through methods of science? no, because than how would the thousands of generations before us, who did not have science and technological advancements be able to come to the conclusion He exists. likewise, how would people living in remote areas where there isn't access to technology, be able to come to the same conclusion. God, being Merciful would not exclude someone the chances of eternal salvation simply because they didn't have access to the right tools. so there must be another method that would be used to discern the existence of God, that can be used throughout history and through a wide scope of socioeconomic conditions more ubiquitous then science. (not to mention, its something you are personally held accountable for, hence the severe punishment of hell.)