Islam... a religion of peace.
Assalam alaikum is the Islamic greeting that means, peace be upon you. It shows the essence of Islam i.e. peace. The Holy Quran says, "Whoever killed a human being, except as punishment for murder or other villainy in the land, shall be deemed as though he had killed all mankind"  Islam condemns terrorism and encourages all mankind to do good to others. Islam is a religion of love, mercy and tolerance.
The Holy Prophet (PBUH) said, "A Muslim is one from whose tongue and hands other Muslims are safe."  It may come as a surprise to non-muslims, because many terrorists belonged to this faith. The truth is that Islam is a religion which is misunderstood by many, though Islam encourages believers to love all mankind.
The Holy Prophet (PBUH) was sent by Allah as a role model for all mankind. He condemned killing or hurting others unless it was in defense or as punishment. The best example of this is the conquest of makkah.  Makkah was conquered without a war. When Prophet (PBUH), entered Makkah, people who lived in that city were scared that Prophet (PBUH) and other Muslims will take revenge from them, but Prophet (PBUH) announced that no revenge will be taken. When the people who had killed his loved ones, were brought before him, he forgave all of them. (Though punishing people for their acts is allowed in Islam, forgiving carries great reward).
Killing others because they don't belong to your faith is the worst of all crimes and Islam condemns it.  Islam preaches freedom of belief and faith and does not allow Muslims to force others to accept their faith. Quran commands, "let there be no compulsion in religion"  The Holy Prophet was commanded by Allah to grant asylum to any unbeliever who asked for it. Islam insists on kind treatment to non-Muslims. It encourages people to live in harmony with others. Islam despises bloodshed.