What is the ruling on acts of worship if they are intended for worldly matters such as happiness or facilitating affairs, and is this intention considered to invalidate the act of worship?

If worship is intended for otherworldly happiness and salvation from punishment, this does not contradict sincerity. Rather, it is the practice of the righteous and their desire for reward and their fear of punishment. And if it is intended for worldly happiness and the facilitation of affairs therein, there is also no harm, for supplicating Allah to mend conditions and relieve distress is praiseworthy in Islamic law. This does not contradict utilizing free time if the intention is good, as Islamic law encourages its utilization. As for matters that vitiate the intention, they involve associating others with Allah in worship.