Matthew 16:18-19 does not expressly give anyone authority to prevent one from communion. It's a statement that "upon this rock will I build my church." It is not a blank check to any man.
1 Corinthians 11:27 warns believers but does not expressly forbid believers from taking communion.
Don't want to keep on this I don't think because the basic Catholic tenants of those two verses, misinterpreted IMO, has been debated for centuries. Nevertheless, even if you grant the Catholic version of Mat 16:18-19, that does not necessarily presume all acts by the Pope are of God nor justify unscriptural acts.
My thoughts, but we'll never solve that part of things here. However, I hope I've helped someone who may be watching.
You’re welcome. No we probably won’t solve anything here tonight but it is good we discuss. For the benefit of the lurkers. I was one of them until recently.
Peace be with you.