Greetings Vipin, and welcome to the forum.
87. We gave Moses the Scripture, and sent a succession of messengers after him. And We gave Jesus son of Mary the clear proofs, and We supported him with the Holy Spirit. Is it that whenever a messenger comes to you with anything your souls do not desire, you grew arrogant, calling some impostors, and killing others?
God sent moses and others to you? who is you here in islamic thinking?
If you go back to 2:40 and 2:47, you will see the verses begin, "O Children of Israel". This passage, mostly addressed to them, continues until 2:123. As you progress in your reading of the translation of the Qur'an, you will come across verses that begin, "O people of the Scripture". These verses address both Jews and Christians. You already came across, 2:21, which addresses mankind/people in general, and there are more. This is a book, for the whole world.
So, the verse you asked about, is addressed to the Jews. It is well known that throughout their history, they denied some of the messengers God sent them; some they rejected, some they blasphemed, and some they killed.
The Prophets are messengers of God. When God sends guidance for human beings, it is through messengers and Prophets, the last of whom was Muhammad (peace, blessings, grace, and salutations of Allah be upon him). God chooses whom He will amongst the noblest and upright of humanity.
When you rebel against a prophet, reject him, blaspheme him, or kill him, you are in effect, rebelling against God. Not because that human being was God, which is not the case, but because God sent him for you, and you reject him and the guidance he was sent with, for you. You are rejecting Gods choice of human being, rejecting Gods guidance.
To reiterate, rejection of any Prophet, is rebellion against God who sent that Prophet, and rebellion against God's guidance and instruction. It is a very serious matter. From their characters and the message they brought, it was not difficult for righteous people at their respective times to know that they were true prophets from God.
Peace.