Why can’t there be one true religion? The existence of multiple religions doesn’t negate the fact that there is one true one. One must wonder why there are so many in the first place? Are they trying to cover up that there is only one true north?
There is absolute truth to who God is and what he is. But it's not likely that there is one true perfect religion. Some religions may be closer to the truth than others, but to hold the view that one religion is 100% correct and every other religion is false is naive. In the Bible it's clear that man's concept and understanding of God is incomplete and often misguided. Even the greatest hero's of the Bible all had incorrect ideas and concepts about God and those ideas led them all to be fallible and prone to mistakes. Why would you think 2000 or more years latter we would be any better at completely understanding God and have arrived at the perfect religion?
The true test of any religion is whether it produces Godly fruit in the person practicing that religion. Otherwise what really is the point? To believe that our eternal destiny is completely dependent on picking the right religion and nothing else is a rather immature and childish idea.
I would say mainstream Christianity in the the United States has a rather poor record in the last 50-75 years. Yes there are many lives that have been totally changed for the better by Christianity, but for every truly changed life for the better there are just as many examples of hard, unloving, judgemental or hypocritical Christians.
My personal sample size of Isalm is to small to come to any real conclusions, but the few Muslims I know presonally have a measure a fruit in their life from their faith. Same with Judasim...my sample size is small but the ones I know appear to be hard hearted and not that loving to the world around them, but only loving to their fellow Jews.
The people I know who claim to embrace Buddist beliefs just seem like decent people who feel that Buddism is the best reflection of their values, but I can't say I personally know of anyone who is a changed person or a better person for embracing Buddism. My very limited exposure to the culture and people of India tells me something similar about Hinduism. (The company I work for built a plant in India 2 years ago. I spent a week in India and interact with our employees from India somewhat regularly).
The bottom line is I presonally have no need to judge or condemn any other religions. The faith I have in the God that Jesus Christ taught and pointed to, is the faith that has produced fruit in my own life and I have personally seen other lives changed by sharing and teaching what I know. So at this point while I question and change any beliefs and doctrines I don't see producing fruit in my life or the lives of other Christians, I have peace that there is truth in the gospel of Jesus Christ. It certianly doesn't mean I believe the current manistream version of Christianity is the perfect, correct or true religion.
In the ages to come we will all learn the perfect and pure unadulterated truth about God. Until then I trust God to lead me and produce fruit in my life and yes I happen to use the Bible as the main inspiration for understanding and learning more about him and the Messiah, Jesus Christ, that he sent.