I guess that could mean several things, but when I say it I mean a Christian who is actively pursuing a Life IN and THROUGH Jesus Christ.
Christianity is kind of like a person joining the Tuscaloosa Running Club. That person has some choices. She can pay her dues, and go to one or two meetings a year (say Christmas and Easter), and never train or run a race, or participate in any other way. Technically she is a member, and can tell all of her friends that, and not be lying.
She can join the Club, attend most all the meetings with enthusiasm, vote, bring up issues to be discussed, even run for office. But also, each day she trains, and helps teach others how to train. She not only attends meeting but participates in running in races, and even helps administer them. If she is a really committed runner, she may even create a road race.
Now, each of these ladies is a Tuscaloosa Running Club member, but in my book:
One is a Practicing Runner, and the other is just a member.
He who has ears to hear, let him hear.