I am an Orthodox Christian and I can tell you that to us, Protestantism definitely looks like a completely different religion.
Despite claiming that they follow Christ, our and their definition of "following" is so different that what they do and believe often looks unrecognizable.
The same can be said about the difference between Catholics and Protestants. Despite our disagreements, the Orthodox and Catholic churches still share a lot theologically. The same cannot be said about Protestants (although, that also depends on what denominations you consider).
It's not to say that we don't share any values. We actually do and there are many individual Protestants that behave in a more Christian way than some members of the Orthodox Church.
However, that is not a highly relevant factor. For one reason or another, there are many atheists and members of other religions that do as well. But those still remain clearly separate and would never be classified as Christians.
Despite claiming that they follow Christ, our and their definition of "following" is so different that what they do and believe often looks unrecognizable.
The same can be said about the difference between Catholics and Protestants. Despite our disagreements, the Orthodox and Catholic churches still share a lot theologically. The same cannot be said about Protestants (although, that also depends on what denominations you consider).
It's not to say that we don't share any values. We actually do and there are many individual Protestants that behave in a more Christian way than some members of the Orthodox Church.
However, that is not a highly relevant factor. For one reason or another, there are many atheists and members of other religions that do as well. But those still remain clearly separate and would never be classified as Christians.