Islam and Roman Catholicism are both political/religious systems - the Vatican is a state with its own ambassadorial representation.
True Christianity is not political; Jesus made a clear distinction between His Kingdom which is a spiritual kingdom and NOT of this world and worldly kingdoms - render unto Caesar… etc.
It is the political/religious nature of Roman catholicism and Islam that make threm so dangerous to life, liberty and happiness. Convert or die is the defining attribute of politico/religious systems. This was understood by Protestant Reformers in Britain and is why RCs were excluded from succession to the throne - although that has been changed in recent years. The Pope has always blasphemoudly claimed to be King of kings (a title that belongs to Jesus Christ) demanding allegiance from mere national sovereigns.