A feeble age

I was reading Surah An-Nahl today, in English the Bee, and came across an ayah which stood out to me:

It is Allah who creates you and takes your souls at death; and of you there are some who are sent back to a feeble age, so that they know nothing after having known (much): for Allah is All-Knowing, All-Powerful. 16:70

This reminded me of my grandfather, who we now know has Alzheimer's in a bad way. What strikes me is that such an illness reminds us that we can forget what we know, and that in reality we have no power... yet the verse ends with the reminder that God is All-Knowing, and All-Powerful. Al-'Alim, Al-Qadeer.

Other verses in this surah are very difficult for me, especially in regards to equality among men. If we are sure that no man is better than another except in piety, why the questions about a slave being equal to his master? What do they mean? What are the answers? Are they not really referring to men at all, but our relationship to God? That we have no power, we cannot provide for ourselves? Are we a burden? I looked into the tafsir a little bit, and saw the explanation of this being the likeness of a believer to a disbeliever. Is this to say that believers are actually all better than disbelievers?

I guess there is a point where we start to see enough in the Qur'an for one day to blow us away. Perhaps it is time then to put it down and reflect... or find someone to answer the questions.