My flavor of religion is not the only right one (Pentecostal). Biblical, historical, orthodox Christianity is the only right one because it follows the only founder who is God and who rose from the dead. If Buddha was God and rose from the dead, I would endorse Buddhism. Since Buddhism is essentially atheistic and Buddha is dead as a door nail, it is a false religion.
The Bible is divine revelation. I would not know about God, Christ, salvation, gospel, etc. apart from this revelation (creation gives general vs special revelation). Christ made claims and proved them by His resurrection. The veracity of my Christian faith rises or falls on the person and work of Christ as revealed in Scripture. Christian apologetics gives more than enough reasons to believe, but most are too lazy or arrogant to do anything other than scoff and mock.
If there is a God, and there is, then He is responsible and has revealed Himself. Hundreds of millions would die for their faith in God that is based on facts, not presumption. We can also show why modern Mormonism, JWs, Christian Science, David Koresh, Jim Jones, Islam, Moonies, etc. are not divine revelation, but counterfeits, false religions. The Word will again be the standard of truth. This is not begging the question/circular reasoning if the Word is in fact from God.