Many commonalities between Muslims and Christians call for cohesion among followers of the two faiths.
When 10-year-old Muhammad (PBUH) was walking in a caravan accompanied by his uncle AbuTalib, Bahira of Busra, a Christian monk, predicted from observations and knowledge in divine books that the boy was to be a great person but with many enemies.
Another aspect of historic nature that unites the two is the statement given by Waraqa, who adopted Christianity and studied religious books of the past, to Khadija the wife of the Prophet (PBUH) assuring her that her husband was going to be the Prophet (PBUH) and that she had nothing to worry about his experiences at Cave Hira where Muhammad (PBUH) first received divine revelation.
These two events are well documented in Muslim classical books on biography of the Prophet (PBUH) and authenticated and both involve Christians well versed in its doctrine concerned about the well-being of the Prophet (PBUH)and his mission before it took off.
Although these narrations may not be supported by Christian sources, the fact that Muslims in general believe in them demonstrate the historic link between the two religions. Islam also mentions Jesus, his mother and disciples highly.
When the Prophet (PBUH) himself got into trouble with Meccans who were then determined to increase pressure on the Prophet (PBUH) and his followers for them to leave their religion, the Prophet (pbuh) found them refuge in Abyssinia (Ethiopia) because it had a just king who would protect anyone within the boundaries of his land from oppression.