These religions all have the Old Testament in common so any of the values and histories presented there are shared by all three religions. They also have the same god in common. Between the religions, there is quite a bit of dispute over the existence and importance of Jesus so you might not want to go there with kids, but it is the same god (as in "the god of Abraham").
Islam, Judaism and Christianity.
Which one of the following elements is common to Judaism, Christianity, Islam, and Zoroastrianis
Both Islam and Christianity originated out of Judaism.
The common ancestor of the three religions Judaism, Christianity and Islam was Abraham
Abraham.
Christianity and Islam are the most common in the world.
Christianity and Islam share a common history and share some of the same beliefs, but they have definite differences...
they are all Monotheistic Religions.
Islam and Christianity
Judaism and Christianity have the bulk of the old testament in common. However Islam draws some of its source material from biblical stories but re-interprets it, so it does not have anything in common in terms of the bible.
They always keep their faith going and strong
Christianity and Islam are the most common religions.