Why did muslims make good soldiers?

Answer 1

If the question is referring to the Rise of Islam period (620s-750), there are several key political and regional reasons why the Arab armies were capable of spreading as quickly and as successfully as it did. (It is worth noting that after this period, the Arabs were never again successful conquerors.)

1) Non-Organization of the Arab Tribes: When Mohammed himself was alive, he concentrated his efforts on uniting all of the Arab Tribes under one banner because they had historically been fragmented. As such, his ability to overtake "the next tribe" became easier due to previous successes. His first successes were based on converting the leaders of those tribes or entering into military alliances with them.

2) Sassanid-Byzantine Foreign Relations: The Sassanid Empire (of Persia) and the Byzantine Empire (of Turkey, the Levant, and Egypt) had considered the Arab Tribes to be cultural and political backwater as they had no civilization of their own nor any united military force which could pose a threat to their conventional armies. Thus, they saw each other as the only real powers in contention for control of Mesopotamia and they bloodied each other real well in this regard. This weakened their overall ability to resist invasions and attacks.

3) Peace After the Fall of the Sassanids: Being the weaker empire, the Arabs attacked Sassanid Persia. However, instead of rejecting their conquerors with long-term occupation, the citizenry was nullified. This is because a number of the Sahaba (or Apostles of Muhammed) were Persians themselves and were able to monitor the situation politically. This allowed the vast majority of Arab forces to turn West on the Byzantines instead of worrying about controlling Persia.

4) The Fall of the Byzantines: The Byzantine Empire was both outstretched and weak from its confrontations with the Sassanid Empire. The Arab forces (along with new Persian regiments) took them both by surprise and at weak, but strategic points. The Arabs did not press their luck into the hills of Anatolia, giving the Byzantine Empire terms for surrender.

5) Peace with the Amazigh (Berbers): West of the Byzantine Empire on the African Continent, the Amazigh Tribes saw no strong reason to oppose the Muslim forces since they had a much more massive force. Many Amazigh leaders converted and joined in the military conquests further westward. It is interesting to note that the majority of Muslims that invaded Spain (including their General al-Tariq - for whom Girbaltar is name) were Amazigh.

Answer 2

Muslim soldires believe if they be killed in the way of God they enter an especial Heaven near God and God provides them. so they do not fear death.