The most obvious answer is that they all believe in the same God. The God of Abraham. I don't know directly how Judaism effected Islam though. But Christianity is very much based on the traditions of Judaism. Ash Wednesday for example is derived from something the Jews used to do to repent for sin. They would cover them selves in sackcloth (burlap) and cover them selves with ash praying to God for forgiveness.
Which is what ash Wednesday for Catholics is derived from. Just Google it though. You'll find tons of answers.
