When a Christian goes into bad habits, sinful behaviour, undesirable or unholy activities he/she is said to have backslider, it is Christian that backslides not unbelievers, the bible reveals God’s contempt against backslider, backsliding attracts God’s judgment, anger and results in closed heavens. Every Christian must be way of backsliding either in word or deeds.
Loss Of First Love For God: The first and greatest command is that we should love God more than all else, a believer backslides when there is loss of first love for God, whatever takes the place of God in your life becomes an cool which can lead to destruction. Rev. 2:4-5, Rev. 3:15-16, Proverbs 14:14a.
Pursuing Temporary Gains at the expense of Kingdom Service and Growth: Backsliding sets in when we place carnal/earthly pursuit before spirituality and service in God’s house. To avoid this we must be focused and noted in Kingdom service. Remember it will be unprofitable to gain the world and lose your soul, Hebrew 12:16-17, Mark 8:36, Mark 10:21, Malachi 3:14.

https://www.guideempire.com/4-ways-to-avoid-backsliding-in-3-minutes/