Of course I don't -- neither history, reason or scripture say so, unless you mean the Catholic Church and the Orthodox Church, and maybe some pre-Chalcedon ones. The communities of faith that emerged from the Reformation are in deep contradiction with the scripture and can lead one away from salvation just as easily as toward it, especially with the indifferentist sentiment that you expressed.
Annalex, the one true church is the entire Body of Christ. Period.