"But they who believe and do righteous deeds - those are the companions of Paradise; they will abide therein eternally."

- Surah Baqarah ayat 82

"Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly.
Allah only forbids you from those who fight you because of religion and expel you from your homes and aid in your expulsion - [forbids] that you make allies of them. And whoever makes allies of them, then it is those who are the wrongdoers."
- Surah 60 ayat 8-9

*the word used for 'fight' here means physical fighting

"And do not insult those they invoke other than Allah , lest they insult Allah in enmity without knowledge. Thus We have made pleasing to every community their deeds. Then to their Lord is their return, and He will inform them about what they used to do."

Surah Al-An'am Ayat 108

*those they invoke other than Allah: those who call out other than Allah, meaning those who call out when they pray other than Allah

The Prophet Muhammad (Sallal laahu alaihi wasallam) has said:

"The best of people are those with the most excellent character." [Tabarâni, Sahîh]

"The best of people are those that bring most benefit to the rest of mankind." [Dâraqutni, Hasan]

"The best of people are those who are best in fulfilling [rights]." [Ibn Mâjah, Sahîh]

"The best of you are those who feed others and return greetings." [Abu Ya'lâ, Hasan]

"The best of you is he from whom good is anticipated and safety from his evil is assured; the worst of you is he from whom nothing good is expected and one is not safe from his evil." [Tirmidhî, Sahîh]

"The best thing mankind has been given is excellent character." [Hâkim, Sahîh]

"The best of the world's women are four: Maryum bint 'Imrân, Khadîjah bint Khuwaylid, Fâtimah bint Muhammad and Âsiyah the wife of Fir'awn." [Ahmad, Sahîh]

*Maryum (Maryam) binte Imran is Mary, Jesus's mother.

"The best of you are those who are best to their families." [Tabarâni, Sahîh]

"The most beloved of people according to Allah is he who brings most benefit, and the most beloved of deeds according to Allah the Mighty, the Magnificent, is that you bring happiness to a fellow Muslim, or relieve him of distress, or pay off his debt or stave away hunger from him. It is more beloved to me that I walk with my brother Muslim in his time of need than I stay secluded in the mosque for a month. Whoever holds back his anger, Allah will cover his faults and whoever suppresses his fury while being able to execute it, Allah will fill his heart with satisfaction on the Day of Standing. Whoever walks with his brother Muslim in need until he establishes that for him, Allah will establish his feet firmly on the day when all feet shall slip. Indeed, bad character ruins deeds just as vinegar ruins honey." [Tabarâni, Hasan]

From: http://steps2paradise.blogspot.sg/2010/11/best-among-you-muslim.html

The Prophet (peace and blessings of Allaah be upon him) made spreading salaam a part of faith. Al-Bukhaari (12, 28 and 6236), Muslim (39), Ahmad (2/169), Abu Dawood (5494), al-Nisaa’i, (8/107) and Ibn Hibbaan (505) narrated from ‘Abd-Allaah ibn ‘Umar that a man asked the Messenger of Allaah (peace and blessings of Allaah be upon him): “What is the best thing in Islam?” He said, “Feeding others and giving the greeting of salaam to those whom you know and those whom you do not know.”

Ibn Hajar said in al-Fath (1/56):

“i.e., do not single out anybody out of arrogance or to impress them, but do it to honour the symbols of Islam and to foster Islamic brotherhood.”

Al-Sanoosi said in Ikmaal al-Mu’allim (1/244):

“What is meant by salaam is the greeting between people, which sows seeds of love and friendship in their hearts, as does giving food. There may be some weakness in the heart of one of them, which is dispelled when he is greeted, or there may be some hostility, which is turned to friendship by the greeting.”

The Prophet (peace and blessings of Allaah be upon him) also explained the reward earned by the one who says salaam, as was reported by al-Nisaa’i in ‘Aml al-yawm wa’l-laylah (368) and al-Bukhaari in al-Adab al-Mufrad (586) and by Ibn Hibban (493). They reported from Abu Hurayrah (may Allaah be pleased with him) that a man passed by the Messenger of Allaah (peace and blessings of Allaah be upon him) whilst he was sitting with some others, and said “Salaam ‘alaykum (peace be upon you).” The Prophet (peace and blessings of Allaah be upon him) said, “[He will have] ten hasanaat (rewards).” Another man passed by and said “Salaam ‘alaykum wa rahmat-Allaah (peace be upon you and the mercy of Allaah).” The Prophet (peace and blessings of Allaah be upon him) said, “[He will have] twenty hasanaat.” Another man passed by and said “Salaam ‘alaykum wa rahmat-Allaahi wa barakaatuhu (peace be upon you and the mercy of Allaah and His blessings).” The Prophet (peace and blessings of Allaah be upon him) said, “[He will have] thirty hasanaat.”

From: http://islamqa.info/en/4596