Because they were hurt by others...
Because they heard hurtful words from others...
Because of difficult circumstances...
Because of someone or something...
Because they failed to pass the desired exam...
Because their wishes were not fulfilled...
However, these are not sufficient reasons.
The real reasons are as follows:

1. When the love for Christ diminishes.
2. When there is little or no time spent reading and meditating on the Word of God.
3. When serious one-on-one communion with the Lord grows cold.
4. When the time for listening to the Word is neglected.
5. When there is no fellowship with genuine people of faith.
6. When sin is committed and there is no repentance.
7. When one looks only at people and not at God.

It is then that faith begins to falter.