All Prophets teachings are universal: worship one and only Allah. Islam set foot on earth since advent of Hazrat Adam (ra) but it was localized.
The Last and Final Prophet Muhammad (saw) "perfected" Islam which is now for whole of humanity.
You will see there are many similarities in Islam and Christianity but there are some inventions by Christians themselves in their own books.
Core teaching is same:
"O Lord, there is none like You, nor is there any God besides You" 1 Chronicles 17:20
Hazrat Isa (ra) was sent for the Bani Israel (the jews).
Every Prophet used to be sent to his nation only but I have been sent to all mankind.' (Translation of Sahih Bukhari, Rubbing hands and feet with dust (Tayammum), Volume 1, Book 7, Number 331)"
Mankind were one community and Allah sent Prophets with glad tidings and warnings, and with them He sent the Scripture in truth to judge between people in matters wherein they differed. And only those to whom (the Scripture) was given differed concerning it after clear proofs had come unto them through hatred, one to another. Then Allah by His Leave guided those who believed to the truth of that wherein they differed. And Allah guides whom He wills to a Straight Path.[2:213]
Surely, they have disbelieved who say: "Allah is the Messiah ['Iesa (Jesus)], son of Maryam (Mary)." But the Messiah ['Iesa (Jesus)] said: "O Children of Israel! Worship Allah, my Lord and your Lord." Verily, whosoever sets up partners in worship with Allah, then Allah has forbidden Paradise for him, and the Fire will be his abode. And for the Zalimun (polytheists and wrong-doers) there are no helpers.[5:72]