A man asked the Prophet for a comprehensive teaching, and he replied:

قُلْ آمَنْتُ بِاللَّهِ ثُمَّ اسْتَقِمْ

“Say: I believe in Allah, then remain steadfast.” — Sahih Muslim

“Indeed, those who say, ‘Our Lord is Allah,’ then remain steadfast — the angels descend upon them…”

“So remain steadfast as you have been commanded.” (Qur’an 11:112)

Uprightness is the natural fruit of sincere belief. First you nurture heart with correct belief, i.e. none has right to worship but GOD; you then align your life in accord by consistently being obedient to GOD in all deed. This includes avoiding major sins and repenting quickly if we make a mistake. Stay balanced not extreme, nor negligent.