James 5:19-20 (KJV)
19 Brethren, if any of you do err from the truth, and one convert him;
20 Let him know, that he which converteth the sinner from the error of his way shall save a soul from death, and shall hide a multitude of sins.
In verse 19 we see that it is possible for Christians to wander away from the truth. Jesus Christ is the truth and His Word is truth. This can happen subtly. Little by little. One starts to think about certain sins one has repented of before and bit by bit slides back to it or one misses one Christian gathering and then the next one and the more we miss the easier it becomes not to gather again. The same can be with prayer, reading the bible etc.. In James 1:13-15 (KJV) it shows the process “Let no man say when he is tempted, I am tempted of God: for God cannot be tempted with evil, neither tempteth he any man: 14 But every man is tempted, when he is drawn away of his own lust, and enticed. 15 Then when lust hath conceived, it bringeth forth sin: and sin, when it is finished, bringeth forth death.”
When we see a brother or sister backsliding we should try to help them to turn back. We can’t make people come back and repent only GOD by His Holy Spirit convicts and it is up to the person to act on that. What we can do besides loving them is to pray for them. GOD can change situations etc. that will help to the person to realise the error of their way and He can then use us to guide then back. Have a read of “The Parable of the Prodigal Son” in Luke 15:11-32.
When a backslider is restored, as part of that restoration, GOD forgives all the sins and the person is saved from destruction and death.
Let us be encourage one another to keep the love for Jesus going and when we see someone that is fading away encourage and help them being guided by the Holy Spirit.
“Hebrews 10:23-25 (KJV) Let us hold fast the profession of our faith without wavering; (for he is faithful that promised;) 24 And let us consider one another to provoke unto love and to good works: 25 Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.”