According to Imam Sajjad (AS), a believer has five characteristics and they are:

1. Avoids committing sins when he/she is alone
2. Pays Sadaqah when his/her financial situation is not good
3. Is patient at the time of calamity
4. Is tolerant at the time of anger
5. Does not lie when he/she is frightened [1].

[1] Al-Khisal, Vol. 1, Page 269.

Source: en.shafaqna.com