Jesus calls His followers "disciples." So He commissioned them to "Go, and disciple (or make disciples among) the nations..."

Non-believers called Jesus' followers "Christians." "And in Antioch, the disciples were first called Christians." (Acts 11:26)

Religion adopted the term Christians as the world called them, instead of what Jesus called them. Thus, degradation set in.

"...For they are not all Israel who are of Israel, nor are they all children (of Abraham) because they are the seed of Abraham..." (Rom. 9:6-7)

"...the blasphemy of those who say they are Jews and are not, but are a synagogue of Satan." (Rev.2:9)