The Eighth Shia Imam, Ali ibn Musa Al-Ridha/Reza (AS) was asked about the characteristics of the best servants of Allah (SWT), and Imam (AS) replied.

1.They are those who when they carry out a good deed, they become happy.
2.And when they do bad acts, ask forgiveness (from God).
3.And when a blessing is granted to them (by God), they give thanks.
4.And when they get into trouble, they wait and they are patient.
5.And when they get angry, they forgive [1].
[1] Tohaful Oqool, Page 332.

Source: en.shafaqna.com