Therefore, it's poorly written.
I agree - within the context of the current time, it is poorly written.
Within the context of its intent, there is not a scintilla of confusion - as evidenced by the customs of the time when it was written, the actions of the people and the inactions of the courts concerning its interpretation and the 2 centuries of common acceptance.
I wish it had been better written as well. But that would not stop the 21st century assault on common sense that is taking place.
No where in the constitution do you find the words 'separation of church and state' yet the current interpretation of the constitution is that it was written precisely to be hostile to religion - at least Christianity in all its forms.