All religions make various truth claims. Some of these fundamental claims contradict each other. So all religions can’t be the same.
For example, several religions believe Jesus was a real person who lived in a specific time and place. However, Christianity teaches that in addition to being human, Jesus was the son of God and came back to life (was resurrected) after being put to death. Islam teaches that he was a only a man, a and was not put to death. And Judaism teaches that Jesus wasn’t a prophet, let alone the son of God.