Preface: I felt the other answers were biased, so I would like to give an unbiased answer, imagining myself as an Atheist
For me there are 2 types of people in this planet,
1.) Group A - Who believe there is something which created The milky way Galaxy.
2.) Group B - There is no one called that 'something' who created it, but everything existed on its own.
(ignore the agnostics for a moment plz)
I belong to this group B.
Frankly speaking, to me, the major difference between the world religions is they differ in the attributes applied to God. Some say, God has son, some say God has daughters, some say God has family, some say God has Avatars, while some other oppose the previous mentioned attributes to some extent, while some other completely oppose any of those attributes and say - God has got no sons, no daughters, no family, no avatars and is just one.
OK. In that group A, let's focus more on the Abrahamic religions, Jews, Christians & Muslims, as they're the sets in the Venn Diagram which claim to overlap at least to some extent onto each other.
After a preliminary level study of these religions, I found the following
History says Jews -> Christians -> Muslims. Even they say, we continue our ancestors.
Major Difference, Jews had/have the problem of Jesus' claiming to be son of God, hence failed/fail to evolve. Similarly, Christians had/have the problem with Muslims while they say Jesus is not the 'only' son of God although they agree he is the son of God(& so are prophets of God). But still, Christians find a suitable reason for their inconvenience they feel when Jesus is not the 'only' son of God, and hence failed/fail to evolve.
Rest of the differences lie in the rituals, practices and other minor derived beliefs etc as they've been taught by their respective prophets(messengers from God).
Blasphemy is found in ascribing to the true God what is false and in falsely denying of God what is true.
I've read somewhere.
So, again as explained before, people differ in the attributes of God, saying each other is blaspheming. If Christians have to accept the attributes applied to God by the Muslims, are alright and cause no problem to the way Christians apply attributes to the Father, then today, Christians would no more remain Christians, but would've surely evolved if they've recognized that the God which Muslims describe is the same God described in Christian Bible. In short - Attributes matter.
Preface: Now I would like to give an opinion imagining I belong to the Group A (See above), and I don't follow any religion in particular, but just believe that there is something called God, who created Mars.
Sure, why is there a single doubt in that, if Muslims claim they don't worship some Moon God, but the God not seen by us and he is always watching us, then why not. What's wrong in their claim.
"When we share the same galaxy, why can't we share the same creator who created it."
Preface: Had to give a christian perspective cuz this a christian site
Believe me when I say that I am in the Father and the Father is in me (John 14:11)
(I don't remember where Jesus said this)
Muslims claim that Jesus and the father are not one. Simple, they don't worship the same God we do. Because we worship Jesus implying we are worshiping the father. But Muslims say that, worshiping Jesus is not equal to worshiping to God, but it is actually analogous to ascribing partners to God and is a greatest gravest sin. So, the basic definitions vary, hence they don't worship the same God.
If we keep the major difference aside, then I don't think there are any other attributes of God as applied by them differ much according to Christian doctrines.
Preface: As you know already, now I'm a Muslim
I would simply add the suffix 'A'layhi Salam' meaning peace and security be on him, just right after the name of Jesus, where ever mentioned above, like this - Jesus (peace be upon him). And the answer to the question Oh! I forgot, obviously we're the ones who made the claim based on Qur'an 2:136, and I can't help if you disregard our claim misunderstanding Bible based on the inferences of the disciples.
And I'm pretty sure, you're gonna down vote this entire answer, just looking at this perspective, overlooking the facts fore mentioned from other perspectives.
I don't mind go ahead.