The Messenger of Allah ﷺ said, "Having a good opinion of Allah is part of the excellent worship of Allah."
حدثنا يحيي بن موسى أخبرنا أبو داود أخبرنا صدقة بن موسى أخبرنا محمد بن واسع عن سمير بن نهار العبدي
قال رسول الله ﷺ إن حسن الظن بالله من حسن عبادة الله
Grading, its isnad is hasan. Abu Dawud reported it in the Book of Manners, chapter on thinking well of others, hadith 4993, from the hadith of Muhammad bin Wasi through the same route. Ibn Hibban graded it sahih, hadith 2395, 2460, and so did Hakim, 4/241, on the criterion of Muslim, and Dhahabi agreed with him. Those who graded it daif are mistaken.