This is a term that is used quite frequently today. A very hurtfull expression to say the least! One own wife directed at me bofore she left. Of course it gave her a solid reason for doing so or did it?
For myself I would be deathly afraid to use such an expression. Why? If we identify ourselves as "CHRISTIAN" should we not very carefully apply all of God's commandments in our lives? If we profess to love Jehovah and we know our Bible we know that 1 John 5:2,3 tells us :"This is what the love of God Means by loving God and carrying out His commandments"
Looking now at one of those commandments in Titus 3:1 we are commanded "to slander no one". Then in Colossians 3:8 we are instructed: "you must rid yourselves of all such things as these anger,rage, mallice,SLANDER"... Then in Colossians 3:8 we read this:"Let your conversation be always full of grace seasoned with salt". We know that salt adds a pleasant taste to many foods. So should not our words be palatable to those listening to us? How long are they going to listen if they are not? Not long eh?
Jesus words at Matthew 12:36 should serve as a caution for all who use expressions like "FILTHY APOSTATE" At Matthew 12:36 He tells us: "I tell you that men (or women) will have to give an account on the Day of Judgment for every careless word they have spoken" One other consideration are Jesus words at Luke 17: 1-3 "It is inevitable that stumbling blocks should come but woe to him through whom they come. It would be better for him to have a millstone hung around his neck and he were thrown into the sea than that he should cause one of these littlo ones to stumble" That statement should be enough to smarten anyone up!
The early Christians were empowered by God to read the heart.Acts 5:1-10 shows this to be true. When the gifts of the spirit ceased so did that particular ability! No one today can read the heart as the early Christians could. So one knows what is really in the heart of any induividual. To term someone else an Apostate is actually saying without saying it "We can read the heart just as Jehovah and His Son can". That is tantamount to "sitting down in the Temple of God professing to be God" That is characteristic of the "Man of Lawlessness" and I might add his followers.
So good reason to stop using expressions like "APOSTATE" or "FILTHY APOSTATE" Time to start behaving like Christians is it not?