Virfidem was coined by Cryptocrew on February 2nd of 2021 in order to describe their experiences. Lots of transmasculine Christians are told they can't be both and that they have to choose either being Christian or being transgender, however, this is untrue.
Vir is man in Latin while fidem is faith in Latin.
The virfidem pride flag is just the trans man pride flag with a Christian cross superimposed to represent Christian trans men. It was designed by Rainbowraven96 (now Reign of the breadsticcs) on February 7, 2021.