أَنْ لَا إِلَهَ إِلَّا اللَّهُ expresses the testimony of Allah’s oneness; أَنَّ مُحَمَّدًا رَسُولُ اللَّهِ affirms the Messenger ﷺ and acceptance of his guidance. These are not merely historical statements; they underpin worship.
تُقِيمَ الصَّلَاةَ emphasizes maintaining prayer, whereas تُؤْتِيَ الزَّكَاةَ concerns an obligatory financial act and the rights of those entitled to it.
For example, maintaining prayer while disregarding financial obligations shows why worship cannot be reduced to one visible dimension of life. Islam involves duties toward Allah and responsibilities toward others.