This question need a full book to answer it. These are few brief facts:

1. Every rule in Islam is based on the benefit of the human being whether we know that benefit or not as it is best known by Allah (SWT).

2. Allah, The Glorious Does not need anything but we need to worship Him properly to live a real human life with peace and success.

3. Worship in Islam is within the limits of our abilities and there is no obligatory worship more than our real ability.

4. More we worship Allah, more we get benefit and elevation and peace of mind.

5. The Prophet Muhammad (SAWA) and his holy Progeny Ahlul Bayt (AS) are the teachers who teach us and all the creatures the real worship of Allah.

I advise you to refer to the sermon of Lady Fatima (AS) in which you will see the wisdom and reasons behind the main worships in Islam.

Wassalam.