Verse 5 says people were commanded to do only this: worship Allah with a sincere heart, keep up the prayer, and give zakah. And then: that is the upright religion.
Notice the first thing on the list is not an action at all — it is sincerity. Doing it because it is Allah you are doing it for, not because someone is watching.
So the religion is not complicated. It is: mean it, pray, and give.