Allah T'ala sent His final Messenger (peace and blessings be on him) as Rahmah (love, compassion and mercy) for all mankind.
Islam is to live as a humble servant of the One and Only One God of all mankind, Allah in complete worship and obedience to Him and Him alone. Prophet Muhammad (peace and blessings be on him) was sent to all mankind with the message and mission to help save themselves from the Hellfire. Islam's message is to be humble to Allah, and be compassionate, loving, giving and caring for all creation. Those who go out and shoot randomly and kill are submitting to the rejected Satan. Such acts are acts of disobedience to Allah and His Prophet Muhammad (s.a.a.w.). Evil does not justify evil.
Help Each Other
"...Help ye one another in righteousness and piety, but help ye not one another in sin and rancour: fear Allah..." (The Holy Quran, 5:2)
O mankind! We created you from a single (pair) of a male and a female, and made you into nations and tribes, that ye may know each other. Verily the most honored of you in the sight of God is (he who is) the most righteous of you. And God has full knowledge and is well acquainted (with all things). (The Holy Quran, 49:13)
Prophet Muhammad (peace and blessings be on him) said: 'O people, listen carefully, your Lord is one Lord, there is no doubt about it. Your ancestor, is one ancestor, there is no doubt about it. Listen well to my words: no Arab has any superiority over a non-Arab, and no non-Arab is superior to an Arab. No black is superior to a brown or red, and no red superior to any black. If there is any superiority in anyone it is due to his God--fearing qualities. (Al-Jamili Ahkam al-Qur'an, 16:342)
No Compulsion in Religion
Let there be no compulsion in religion: Truth stands out clear from Error: whoever rejects evil and believes in God has grasped the most trustworthy hand-hold, that never breaks. And God hears and knows all things. (The Holy Quran, 2.256)
Murder and suicide
…if any one slew a person - unless it be for murder or for spreading mischief in the land - it would be as if he slew the whole people: and if any one saved a life, it would be as if he saved the life of the whole people….(The Holy Quran, 5.32)
O ye who believe! Eat not up your property among yourselves in vanities: But let there be amongst you traffic and trade by mutual good-will: Nor kill (or destroy) yourselves: for verily God has been to you Most Merciful! (The Holy Quran, 4:29)
O ye who believe! stand out firmly for justice, as witnesses to God, even as against yourselves, or your parents, or your kin, and whether it be (against) rich or poor: for God can best protect both. Follow not the lusts (of your hearts), lest ye swerve, and if ye distort (justice) or decline to do justice, verily God is well-acquainted with all that ye do. (The Holy Quran, 4:135 )
"Do not let your hatred of a people incite you to aggression." (The Holy Quran 5:2)
"And do not let ill-will towards any folk incite you so that you swerve from dealing justly. Be just; that is nearest to heedfulness." (The Holy Quran 5:8)
Peace with Superior Good
Good and evil are not equal. Repel (evil) with that which is good, and you will see that he, between whom and you there was enmity, shall become as if he were a bosom friend (of yours). (The Quran: 41:34)
A man asked the prophet (peace and blessings be on him), "what in Islam is the best?" He answered, "To feed people and to say salam (greetings of peace) to everyone whether you know them or not." (Bukhari and Muslim)
Do no mischief on the earth, after it has been set in order, but call on Him with fear and longing (in your hearts): for the Mercy of God is (always) near to those who do good. (The Quran, 7:56)
Prophet Muhammad (peace and blessings be on him) said:"Those who show mercy have God's mercy shown to them. Have mercy on those here on earth, and the One there in Heaven will have mercy on you." (Imam Ahmad)
Prophet Muhammad (peace and blessings be on him) said:"A believer is not the one who eats his fil while his next door neighbor goes hungry." (Al-Bukhari)
Jihad is an on-Going Struggle against Evil
For Muslims and in fact all of mankind, the struggle between good and evil began with eating from the forbidden tree and it will continue at personal, family, community, national and international levels till the end. The real and ultimate success in this life-long struggle is for those who are good in their hearts and good in their works, and God is good. Let us help and cooperate in piety and God-fearing with our hearts and with our works and distance ourselves from sin and rancor with our hearts and with our works, for the sake of God and for the love of God.
Supplication For Peace
O God! You are the Peace. The everlasting peace is from You. O Glorious and Bounteous One! You are Blessed and Majestic. (Sahih Muslim)