To many, the issue of issue over whether a person is an Arminian or Calvinist comes down to whether or not a person believes that they can lose their salvation. Those who only hold to the doctrine of eternal security or “once saved, always saved” may be considered one point Calvinists.
One point Calvinists may hold to Arminian doctrine with the exception of the issue of eternal security or they just may not have any formed beliefs regarding the other points of Calvinism outside of the security of one’s salvation.
Because the issue of eternal security is so key to many Christians’ beliefs, a person may hold to four points of Arminian doctrine but still call themselves a one point Calvinist because the one point is most important to them.
Unlike Calvinists, Arminians do not tend to identify themselves with how many points of Arminianism they believe in.