If a person utters the name Jesus does that make him a Kufr because christans and Catholics say it so if a Muslim were to say it you would be acting like a Christian or a catholic therefore makes you Kufr?
‘kufr’ refers to the denial of anything Allah obliges belief in, whatever the Prophet (saw) brought from Allah proven definite and certain; having belief in that with one’s heart that it’s the truth is necessary for one to be a Muslim (believer). Therefore, a person who does not consider any of the definite teachings of the Prophet (saw) to be true or does not approve of them is called a ‘kafir’ (disbeliever). So if one says Jesus just as a name is not a Kaafir. The one who utters it with belief is... Read the following article to understanding what 'kufr' is in Islam. This will provide a clear view on how to determine kufr https://www.islamiqate.com/3998/what-is-the-concept-of-kufr-in-quran.