Rasulullâh Sallallâhu 'alayhi wasallam has informed us that Hadhrat Îsa Alayhis Salâm shall return to this world just before Qiyâmah to slay Dajjâl. He will then pass away naturally. However, the Christians adamantly believe that he was crucified.
The Christians were just as opposed to Islâm as the Jews were. Therefore, Allâh instructed Rasulullâh Sallallâhu 'alayhi wasallam to issue a challenge of Mubâhala to them. The term Mubâhala is a challenge between two opposing factions where each gathers his family members and they collectively invoke Allâh's punishment on the opposite faction saying, "O Allâh! Curse the party of us that is false and lying." However, the group of Christians whom Rasulullâh Sallallâhu 'alayhi wasallam challenged shrank in fear from the challenge.
This part of Sûrah Âl Imrân discusses both the Battle of Badr as well as the Battle of Uhud. During the Battle of Badr the Muslims were only 313 in number and did not even have sufficient arms to fight with. On the other hand, the Mushrikîn were over a thousand and were armed to the teeth. However, Allâh sent thousands of angels to assist the Muslim army and they convincingly vanquished the enemy. This battle was the first battle that the Muslims fought.