Inasmuch as they have faith in Christ, repent of their sins, and keep the commandments, they are followers of Christ.
Inasmuch as they follow doctrines of men, like Sola Scriptura, they are followers of human tradition.
This is why Christ's Church teaches that followers of Luther are imperfectly united to the Body of Christ, to varying degrees.
"If he will not listen to the church, treat him as a pagan or tax collector." --Jesus
Jesus gave His Church, the "pillar and foundation of truth," the Authority to teach and to discipline --to bind and loose. Christ did not give this Authority to Luther or Calvin, or any of their disciples.
"Go and make disciples of all the nations... teaching them everything I have commanded you." --Jesus
“If he will not listen to the church, treat him as a pagan or tax collector.” —Jesus
ALERT - repetitive out of context distortion of the words of Christ in Scripture
Posting it as if it were will lead someone to the wrong interpretation of that passage.
What Jesus said when He spoke those words, is: Matthew 18:15-18 If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother. But if he does not listen, take one or two others along with you, that every charge may be established by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the church. And if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector.
For all the criticism non-Catholics receive about cherry picking verses and taking them out of context, there is simply no way anyone is going to one up this abuse of Scripture.
Taking a fragment of a sentence and posting it as a command of Jesus' is the ultimate in cherry picking verses to support a doctrine.
It will lead to deception.
This passage is only about settling personal disputes between individual believers, and the taking it to the church part is the LAST step in in process.
What it most certainly is NOT is a blanket command by Jesus to listen to, or submit to, the Catholic church.
The body of Christ, not the Catholic church, is the pillar and foundation of the truth. It is NOT the truth itself.
I realize that Catholics wish with their whole hearts that non-Christians would be followers of men, but it's just not so. Nobody is following Luther just because they believe that Scripture is the final authority and that it contains all we need to know pertaining to life and godliness.
Simply because two people come to the same conclusion based on the evidence, does not by default mean that one is a follower of the other. That's a misinterpretation of the evidence. No surprise coming froma Catholic.