Of course that claim is extremely important. But you keep confusing that singular issue with the complex issue of religion in general. Theism and religion is a vast subject which has involved billions of people over all the centuries of recorded human history, with huge variations of beliefs about God (gods) and religion (worship of said deities).
I don't care to discuss religion half as much as I care to discuss God. As God is Spirit, there is no scientific experiment that can 'prove' His existence, so God has kindly sent into our midst one who is human, but perfect and from Him - the exact representation of God's very being (as stated in His written communication to us.) That One leads us to the reality of the one God who created everything. Christians have discovered the truth of that, so if you care to consider the person of Jesus of Nazareth, we could discuss Him and see where that gets us with regard to the reality of God. After all, He claimed that He is The Truth, in His person. Interested? (No, I thought not...)