The Messenger of Allah ﷺ said: By his good character a believer will attain the degree of one who prays during the night and fasts during the day. (Using translation from Abū Dāʾūd 4798)
"إِنَّ الْمُؤْمِنَ لَيُدْرِكُ بِحُسْنِ الْخُلق دَرَجَةَ الْقَائِم الصَّائِم ".