The reasons will be different for different people, but the sad fact is that some people do make a commitment to God and his son and later renege on it. Jesus spoke of it as “putting their hand to the plow and looking back” (Luke 9:63) and warned that such people were unfit for the kingdom of God.
Jesus told some parables with examples of people who left their faith. One was the parable of the sower (Matthew 13:3-9, 18-23; Mark 4:3-8, 14-20; Luke 8:5-8, 11-15). In this parable, Jesus speaks of 4 categories of people and 2 of them relate to people falling away from God. One group of people is pictured as seed falling on rocky ground, growing up quickly but withering when the hot sun shines on them. Jesus interprets this to describe people who immediately receive Christianity with joy, but when life becomes difficult, they give up. Another group is described as growing up in the middle of thorns and being strangled by them. Jesus explains that these are people who fall away from Christianity because of the cares of this world. In the same way, Paul describes a man called Demas as having deserted him because he was in love with this present world (2 Timothy 4:10).
Some reasons for falling away from faith are described as:
|Name(s)||Why or how they fell away|
|Judas||probably love of money (Matthew 26:14-16)|
|Ananias and Sapphira||lying in an attempt to gain respect among believers for their generosity while still keeping some money for themselves (Acts 5:1-5, 7-10)|
|Demas||in love with this present world (2 Timothy 4:10)|
|Hymenaeus and Alexander||rejecting faith and a good conscience (1 Timothy 1:19-20)|
|Hymenaeus and Philetus||irreverent babble leading to more and more godlessness – swerving from the truth (2 Timothy 2:16-18)|
|Unnamed brother||sexual immorality and a refusal to accept it was wrong (1 Corinthians 5:1-13)|
|Diotrophes||Liked to put himself first, spoke wicked nonsense and would not listen to the apostle John (3 John 9-10)|
|Jezebel||sexual immorality and teaching encouraging others in sexual immorality and eating food offered to idols (Revelation 2:20-23)|
|some in Laodicea||some who held the teaching of non-believers – Balaam and the Nicolaitans – leading to sexual immorality (Revelation 2:14-16)|
Some of those who stop following Christ will leave the congregation, but some will not. The second group are the more dangerous. Paul says of Hymenaeus and Philetus that their talk would spread like gangrene (2 Timothy 2:17-18). Jesus also told a parable about weeds and wheat being left to grow together until the harvest – a parable he explained to mean that there would be faithless people among the faithful, right up until the judgement. In this we are warned that there will always be opposition to those who hold on to faith in God.
The prodigal son is another parable about this subject (Luke 15:11-32), but it is one with some hope for the one who leaves his calling. After selfishly leaving his family and wasting his inheritance, the prodigal son repents, returns, and is welcomed back (Luke 15:21-24).
Also, those who are in the process of falling away but probably did not realise it, were warned by Jesus in his letters in Revelation and these remain warnings to us today:
|Congregation in Ephesus||had lost their first love (Revelation 2:1, 4-5)|
|Congregation in Laodicea||showed apathy – “lukewarm” (Revelation 3:14-19)|