Over at Pulpit & Pen Matt Sherro puts forward what he believes are the characteristics of apostates:
There is a danger that has come into the sheepfold; apostates have come in and they probably have always been here. However, with the prevalence of social media, their influence has spread and it is more important than ever before to recognize the marks of an apostate, a person who at one time knew and maybe even taught the truths of the Bible but walked away or a person who consistently teaches false doctrines to the Church. Jude, the Lord’s youngest human brother, points out several signs of an apostate and I want to draw your attention to them.
Book of Jude (HCSB),
1 Jude, a slave of Jesus Christ and a brother of James: To those who are the called, loved by God the Father and kept by Jesus Christ.
2 May mercy, peace, and love be multiplied to you.
3 Dear friends, although I was eager to write you about the salvation we share, I found it necessary to write and exhort you to contend for the faith that was delivered to the saints once for all. 4 For some men, who were designated for this judgment long ago, have come in by stealth; they are ungodly, turning the grace of our God into promiscuity and denying Jesus Christ, our only Master and Lord.
Right away we begin to see the characteristics of the Apostates that Jude warns about…