The definition of Islam is the acceptance, submission, sincerity and belief of the One God - Allah, (the Creator of the Universe) and to worship Him alone without any partners or any part of His creation. The word Islam comes from two root words, "submission" or “surrender” (to God) and “peace” (Arabic - salima: with God and within oneself). In general, of course Islam allows Muslims to live in peace with its neighbours unhindered. When Muslims greet each other they exchange peace with each other i.e. peace be upon you (Arabic - assalaamu aleykum).
“Therefore turn your face steadfastly towards the true faith (Islam), away from all that which is false, in accordance with the Pure nature with which Allah has Created people. Let there be no altering in the laws of Allah's Creation. This is surely the true religion, but most people do not know it.”
Qur’an - Surah ar-Rum (The Romans) 30:30
A person who obeys and worships the One True God is a Muslim. This defines theword Muslim. Adam and Eve (peace be upon them) were the first Muslims and Adam was the first prophet of Islam.
“The Religion in the sight of Allah is Islam.”
Qur’an - Surah al-`Imraan (The Family of `Imraan) 3:19
And this was the legacy that Abraham left to his sons, and so did Jacob; “Oh my sons! Allah hath chosen the Faith for you; then die not except in the Faith of Islam.”
Qur’an - Surah al-Baqara (The Heifer) 2:132
Each new person born into this life is a Muslim. This is because, when our souls were created, we testified to the belief of the One God as the following Qur’anic verses shows.
172. And (remember) when thy Lord brought forth from the Children of Adam, from their reins, their seed, and made them testify of themselves, (saying): Am I not your Lord? They said: Yea, verily. We testify. (That was) lest ye should say at the Day of Resurrection: Lo! Of this we were unaware;
173. Or lest ye should say: “Our fathers before us may have taken false gods, but we are (their) descendants after them: wilt Thou then destroy us because of the deeds of men who were futile?”
174. Thus do We explain the signs in detail; and perchance they may turn (unto Us).
Qur’an - Surah al-A`raaf (The Heights) 7:172-4
Hence our innermost nature (fitra), from the moment of our birth, is to accept the existence and belief of the One God, our Creator. Consequently we are all born pure into this world as Muslims.
35. O ye Children of Adam! whenever there come to you messengers from amongst you, rehearsing My signs unto you,- those who are righteous and mend (their lives),- on them shall be no fear nor shall they grieve.
36. But those who reject Our signs and treat them with arrogance,- they are companions of the Fire, to dwell therein (for ever).
Qur’an - Surah al-A`raaf (The Heights) 7:35-6
Who has created death and life, that He may test you, which of you is best in conduct; and He is the All-Mighty, the Oft-Forgiving;
Qur’an - Surah at-Talaaq (Divorce) 67:2 See also 6:18.