God kinda did do that though. And it can be claimed by the Roman Catholic, Orthodox Catholic, and Oriental Orthodox churches are the "true church"
Personally I tend to go with a big tent approach. Basically, as best I can gather, right now we are fighting an inter-dimensional war with demons for the souls of all mankind and Jesus Christ ie God is on the good side. So we pretty much need all the help we can get. As long as churches are based and believe in one God, the father, son and holy spirit who was crucified and rose from the dead, I think we can work together and work out the details later. Except for Angelicans, their heresy knows no bounds.
The "true" church came about in the first century. Catholicism didn't come about until somewhere in the 300's.