But you are not like
Prophet Joseph who believed in all the prophets of God,
while
Jews and Christians discriminate in their belief: they believe in some and deny other prophets:
so Jews disbelieve in Jesus and Mohammed, and Christians disbelieve in Mohammed, while Muslims believe in all God's prophets including Abraham, Moses, Jesus and Mohammed.
[Prophet Mohammed – salam to him – invited the People of the Bible [: Jews and Christians] to the Islam, and some of them converted and became Muslims, while others denied his prophet-hood and demanded many impossible requests from him; therefore, God revealed these ayat about them:]
Quran 4: 150-151, which mean:
(
150. Those who disbelieve in God a and His apostles [: messengers], and intend to discriminate God from His apostles [by denying some of the apostles], and say: "We believe in some [of the prophets] and disbelieve in others", and intend to take a course midway [between guidance and misguidance.]
151. These really are the disbelievers, and We have prepared for the disbelievers a humiliating punishment.)
......................................................................
150
a i.e.
Jews who worshiped the idols.
And
Christians who also disbelieved in God: because they claimed about the Trinity, and said the Christ is the son of God
((while the Christ himself rebuked Peter and drove him away, because he said about him: “You are the Messiah, the Son of the living God.”; and he did not accept him till the disciples interceded for him; the Christ said to him: “Get behind me, Satan! You are a stumbling block to me; you do not have in mind the concerns of God, but merely human concerns.” – Gospel of Matthews chapter 16: 22))
while other Christians said: the Christ is God Himself. Therefore, this is their disbelief in God.
More explanation by Mohammed-Ali Hassan Al-Hilly:
http://quran-ayat.com/pret/4.htm#a4_150
quran-ayat.com/pret/4.htm#a4_150