Some of the traits of Muslims who lived in times of greatest success were as follows...
People of wisdom state:
If the reasons that lie behind the success of Muslims throughout history are examined, it will be seen that it was due to their adherence to the religion [Islam]. Actually, the degree of success is dependent on the degree of obedience to our religion. Therefore, one's success is in direct proportion to one's obedience to the religion. Anyone who obeys it fully will be fully successful. In our religion, what will be done and how it will be done is fixed. The more one puts this into practice flawlessly, the more success one achieves.
Some of the traits of Muslims who lived in times of greatest success were as follows:
1. They were compassionate toward everyone, the faithful or the faithless, surely with the exception of cases that necessitated having a dislike for the sake of Allah. If anyone displayed enmity against the religion [Islam], then he/she used to receive a harsh treatment from them. As a matter of fact, Allahu ta'ala praises the Blessed Companions in the Qur'an al-karim, saying, "They love one another much. They are very merciful to one another but very stern and unyielding toward Allah's enemies."
2. They were like one body. A head, hands, and feet are of the components of the body. If any component of it is suffering, it affects the entire body. Hence, success is dependent on the body's enjoying good health.
3. They were like one heart. They used to share the same faith and feel the same joy and sorrow.
4. They had only one purpose, goal, and target, which was Allahu ta'ala's pleasure.
5. They used to obey the ruler and did not rise in rebellion against him. They did not use to instigate mischief or anarchy.
6. They used to work day and night with pure intention so that one more human could be saved from burning.
7. They were extra scrupulous about obeying our religion.
8. They used to say, "We should lead such a life that no one will go to Hell because of us. Let Allah's servants pronounce benedictions over us, not maledictions."
9. They did not use to lie or talk about people behind their backs or gossip. They used to make du'a [supplication, prayer] for one another. They were well aware that a du'a that is done for another in his/her absence and without expecting anything in return was acceptable.
10. They used to attach great importance to do good and to win a du'a.
Charity averts calamities. Du'a changes divine decree. One day, Jibrail 'alaihis-salam came to our master the Prophet and informed him that a certain young man would die that night. Thereupon, our master the Prophet summoned that young man and asked him whether he had any wish. He told him he wanted to get married. Then he was married off right away. That night he and his wife performed salat and made du'a. When they were just about to eat the dishes prepared for them, a poor person came to the door and asked for food. They gave all of the food to him. Being very pleased with it, he made a du'a for them and went away.
The morning came. Our master the Prophet was waiting for the news of the death of that young man. There being no news, he sent someone. The message bearer returned and said that the young man was alive and in high spirits. Jibrail 'alaihis-salam came and informed our master the Prophet that the young man gave his own food to a poor person the previous night and that Janab-i Haqq [Allahu ta'ala], therefore, lengthened his lifetime because of the poor one's du'a for him. He requested them to look under the pillow. They found a dead serpent under his pillow. It was understood that the serpent could not bite the young man thanks to the charity he gave and the du'a made by the poor one.