What does Islam have in common with Judaism and Christianity?

Answer 1

There isn't much, but here is a short list of commonalities:

1. Abraham is the common root for all three.
2. All three believe in One God i.e. All three are monotheistic faiths.
3. All three revere acts of kindness (Meccan suras, not later Medinan suras)
4. All three have a code of behavior

They are the three major Abrahamic religions. Abrahamic religions are monotheistic religions, i.e. only one god, that can all trace their belief systems back to an origin or spiritual connection to Abraham. Judaism was founded first, followed by Christianity in the first century, and Islam in the seventh century.

The father of all three religions was Abraham. Abraham's eldest son was the father of the religion of Islam, and Isaac, יצחק, was the father of Judaism, and Christianity broke of from Judaism when they thought Jesus was the Messiah.
Common with whom/what

Answer 2

There isn't much, but here is a short list of commonalities:

1. Abraham is the common root for all three.
2. All three believe in One God i.e. All three are monotheistic faiths.
3. All three revere acts of kindness (Meccan suras, not later Medinan suras)
4. All three have a code of behavior

They are the three major Abrahamic religions. Abrahamic religions are monotheistic religions, i.e. only one god, that can all trace their belief systems back to an origin or spiritual connection to Abraham. Judaism was founded first, followed by Christianity in the first century, and Islam in the seventh century.

The father of all three religions was Abraham. Abraham's eldest son was the father of the religion of Islam, and Isaac, יצחק, was the father of Judaism, and Christianity broke of from Judaism when they thought Jesus was the Messiah.
Common with whom/what

Answer 3

In reality, there really is no similarity to best describe the Judeo-Christian beliefs of God to the Muslim Islamic belief. Judaism and Christianity have the Old Testament in common. Islam believes both OT and NT have been partially corrupted in transmission while the Koran is believed by Muslims to be the final and infallible revelation of God's will. Though Muslims believe in God which they call Allah, Islam teaches that Allah is all-powerful, sovereign and 'unknowable' while Judaism and Christianity both teach the Creator God to be revealed as merciful, compassionate and knowable (see Jeremiah 9:24 and John 17:3).

The Christian text teaches the God of the Old Testament was the Word and it was He who Abraham and the other patriarchs and prophets worshiped. Islam teaches the Word, aka Jesus 'as one of perhaps 124,000 messengers of prophets Allah has sent and is one of the 25 listed in the Koran - but He is not the redeemer' (Marvin Olasky, "Islam vs. Liberty," World, Sept 10, 2011). All in all, there are more differences and conflicts between the Judeo-Christian texts and the Muslim text, as well as the Koran conflicts with secular history.