Was reading an article on Islam, it referenced Quran 2:136, it appears to me that all scripture, no matter the source, are accepted by Muhommed. Can you explain?
I'm not that knowledgeable, but Muslims believe that Islam (submission to God) religion (way of life) has been there since man set foot on earth (with Adam). Muhammad (pbuh) is the last and final messenger of God. There were many, many more messengers before him Adam, Jesus, Moses etc. And they all taught about the oneness of God. Their day to day laws might differ, depending on the time etc, but the tawheed (Concept of God) was the same. Thus, by believing the last message, you have actually believed in all the messengers before Muhammad (pbuh). I'm not saying this is what the ayah means but I hope this might help.
In The Name of Allah, The All-Merciful, The Ever-Merciful,
All Perfect Praise be to Almighty God,
and prayers and peace be upon the Messenger of Allah and his family and companions,
Having said that,
Peace be upon those who follow guidance
Important note about your question :
In your question you say "no matter the source" and this is wrong understanding, the source is one and only one : Allah (God) the creator of everything and its owner, Our God and the God of our fathers, He is the One who sent all the messengers and prophets to the humans and revealed the holy books to them so they can teach the humans on how to worship God.
The belief for Muslims consists of the following : 1- Belief in God. 2- Belief in God's angels. 3- Belief in God's books (scriptures). 4- Belief in God's messengers. 5- Belief in the Judgment day. 6- Belief in God's fate and destiny. the denial of any part of this belief leads to the denial of the belief in general, that's why we Muslims believe in all messengers and the scriptures.
further to that let's explain the verse the article has referenced.
Surat Al-Baqarah (The Cow) - which derives its name from the story of the cow of the Jews - included more than one hundred and fifteen (115) verses that spoke about the Jews, representing 40.20% Of the total number of verses of this 283 verses.
this is the verse you are talking about :
God Almighty said (to the believers) : ("Say, “We believe in God; and in what was revealed to us; and in what was revealed to Abraham, and Ishmael, and Isaac, and Jacob, and the Patriarchs; and in what was given to Moses and Jesus; and in what was given to the prophets—from their Lord. We make no distinction between any of them, and to Him we surrender.”")(Surat Al-Baqarah:136)
If you are looking to understand this verse, we have to understand the context that it is brought in, lets see what is the preceding verse (no. 135)
God Almighty said : ("And they say, “Be Jews or Christians, and you will be guided.” Say, “Rather, the religion of Abraham, the Monotheist; he was not a polytheist(idolater).”")(Surat Al-Baqarah:135)
This is a clear sign that the Jews and the Christians have changed their religion and moved away from the religion of Abraham, "Hanifiyya", which calls for the worship of one God
Then, if we move to the later verse (no. 137)
God Almighty said : ("If they believe in the same as you have believed in, then they have been guided. But if they turn away, then they are in schism. God will protect you against them; for He is the Hearer, the Knower. ")(Surat Al-Baqarah:137)
This verse contains the answer to your question, now lets build our understanding to these 3 verses for a clear view for the context :
1- the Jews and Christians say to you (Muslims) to follow them for guidance.
2- God says to the Muslims that they should follow the path of Abraham (prayers and peace of Allah be upon him and his family) which is the path of Monotheism.
3- God says to the Muslims to reply to the call of the Jews and Christians (1) with this answer (We believe in God and what was revealed to all these prophets (Abraham, Ishmael, Isaak, Jacob and his sons, Moses, Jesus, and all other prophets) making no distinction between them, and the Jews and Christians have to believe in this too like the Muslims.