Many Christians backslide because this truth is not clearly taught. Some are unable to stand against temptation or their old nature.
Though they strive to do their best to fight against sin and to serve God, they have no strength. They have never really grasped the secret that the Lord Jesus will continue His work in the believer every day from heaven. But there is one condition: Time alone with the Lord Jesus each day is the indispensable condition of growth and power.
Read Matthew 11:25–30