Among the signs of backsliding are indifference to prayer and self-examination; trifling or unprofitable conversation; neglect of public worship; shunning the people of God; association with the world; thinking lightly of sin; neglect of the Bible; and often gross immorality.
- C. Buck (moreillustrations.com)
Heb 6:4-6 (NHEB): "For concerning those who were once enlightened and tasted of the heavenly gift, and were made partakers of the Holy Spirit, and tasted the good word of God, and the powers of the age to come, and then fell away, it is impossible to renew them again to repentance; seeing they crucify the Son of God for themselves again, and put him to open shame."
"Backsliding, generally first begins with neglect of private prayer." - J.C. Ryle.