If Christ Jesus exists, then there is only one denominational church that exists... And the denomination of this church is Jesus.
That's it... Simply, Jesus.
You want to be a part of the one true church... Be a part of Jesus, as a member of His one Body, of which He alone is the Head.
It's really not rocket science... Even a bunch of ancient, many uneducated, people were able to grasp it... And their response was to simply say that they were followers of the Way... This Way being... The Person of the Lord, Himself, who was dwelling in them, if they were born-again of God.
The one true church... Really, the only church that the Lord is building... Is the dwelling place of God in spirit (Eph. 2:22).
And it's when a believer sees this reality, and lives according to it, that this believer has entered into the reality of the one church of God.
Amen.