Morality in Islam

As-Salam-U-Alaikum

In Islam, why must we follow Allah's commands?

For example, does Allah give a reason for his prohibition of murder?

Or must we simply obey His commands, without being given a reason?

And if we do not know the reason for His commands, how do we know that they are good?

Bina

If you read Quran and follow Quran then you will be the best person in Sha Allah look at some commandments by Allah
Ch 2 v 177
It is not righteousness that ye turn your faces Towards east or West; but it is righteousness- to believe in Allah and the Last Day, and the Angels, and the Book, and the Messengers; to spend of your substance, out of love for Him, for your kin, for orphans, for the needy, for the wayfarer, for those who ask, and for the ransom of slaves; to be steadfast in prayer, and practice regular charity; to fulfil the contracts which ye have made; and to be firm and patient, in pain (or suffering) and adversity, and throughout all periods of panic. Such are the people of truth, the Allah-fearing.

Ch 17 v 23
Thy Lord hath decreed that ye worship none but Him, and that ye be kind to parents. Whether one or both of them attain old age in thy life, say not to them a word of contempt, nor repel them, but address them in terms of honour.

Ch 17 v 24
And, out of kindness, lower to them the wing of humility, and say: "My Lord! bestow on them thy Mercy even as they cherished me in childhood."