The most complete of the believers in faith are those with the best character.

Abu Hurairah - Sunan Abu Dawud & Tirmidhi

The strong believer is better and more beloved to Allah than the weak believer, while there is good in both.

Abu Hurairah - Sahih Muslim

The strong person is not the one who can overpower others. Rather, the strong person is the one who controls himself when he is angry.

Abu Hurairah - Sahih Bukhari & Muslim