“There is only one holy Christian church. We cannot see it, but this assembly brings together everyone who has faith in Jesus Christ as Savior.
The true church includes people from many denominations, even Catholic. But it is not exclusive to Catholics.”
That’s not what the bible teaches, unfortunately. The Church is the Bride of Christ. This is not an ‘invisible’ union, just as we ought not marry in secret. This is a visible union.
Together all believers form the holy Christian church, a “spiritual house” made up of living stones chosen by God. When the Holy Spirit works faith in our hearts, we become part of this structure. The Lord Jesus can see the faith in our hearts. We, however, can only see the fruits of faith and not the faith itself. Because we cannot see faith, the church is invisible to our eyes.