اتَّقِ اللَّهَ establishes the inner standard of mindfulness. أَتْبِعِ السَّيِّئَةَ الْحَسَنَةَ offers a path of recovery after a lapse. خَالِقِ النَّاسَ بِخُلُقٍ حَسَنٍ makes that improvement visible in the way others are treated.
A person might act honestly when alone but regularly speak harshly to family; good character still needs work. Another might smile warmly while withholding people’s rights; appearances are not enough.
Together, these clauses link conscience, correction, and social responsibility, rather than treating each as an unrelated instruction.