Go to Saudi Arabia (or any other Muslim country for that matter) and proclaim; "God is a Spirit!".
See how fast they chop your head off.
Proclaim "God has a Son, Jesus Christ!" and they might behead your family too.
I'm not here to defend the peculiar theology of religions not in communion with the Roman Catholic Church.
I just posted the official Catholic position.
Since Protestants and Catholic have never agreed on certain theological issues for centuries, there is nothing I can say to convince you.
You can always demonize any religion by selecting quoting and biased reporting of its beliefs.