NassirUDeen writes "Allah has extolled the virtues of the Companions of the Prophet (sas) many places in the Qur'an. A Companion is defined as one who met the Prophet (sas) in a state of belief and who died in that state. Allah said (after mentioning some of the hypocrites who stayed behind from Jihad): {Rather, the Prophet and those who believe with him fought with their property and their lives for these are all good things, they are the successful ones and Allah has prepared for them gardens beneath which rivers flow therein forever and that is the great success.} At-Tauba: 88-89

All praise is surely due to Allah Most High. We praise Him, seek aid ONLY from Him, seek forgiveness ONLY from him and seek guidance from Him. We seek refuge in Allah from the evil within ourselves and the wicked among our deeds. Whoever Allah guides, none can lead astray and whoever Allah decrees to go astray, non can guide. I bear witness that there is no deity but Allah and I bear witness that Muhammad (sas) is his slave and messenger. Allah has extolled the virtues of the Companions of the Prophet (sas) many places in the Qur'an. A Companion is defined as one who met the Prophet (sas) in a state of belief and who died in that state. Allah said (after mentioning some of the hypocrites who stayed behind from Jihad): {Rather, the Prophet and those who believe with him fought with their property and their lives for these are all good things, they are the successful ones and Allah has prepared for them gardens beneath which rivers flow therein forever and that is the great success.} At-Tauba: 88-89 Allah's praise of the Companions also extends to all those who follow their way. Allah said: {The forerunners those who came first among the Migrators and the Helpers and those who followed them with the best. Allah is pleased with them and they are pleased with Him and Allah has prepared for them gardens beneath which rivers flow therein forever and that is the great success.} At-Tauba: 100 The best generations of all time are: the generation of the Prophet (sas) i.e., the Companions, those who followed them (at-taabi'een) and the ones who followed those (atbaa' at-taabi'een). They are our best example. When we doubt whether a certain practice or belief is a prohibited bid'a or a valid interpretation and a good practice in the din, we simply have to look at these generations. If it is in the area of worship and they did not practice it or anything similar to it, or they openly condemned it then we know with certainty that it is not part if Islam and is the bid'a which Allah and His Prophet (sas) have absolutely forbidden. The Prophet (sas) said: "The best of my nation is my generation then those who follow them and then those who follow them." Sahih Bukhari The word for "generation" is qarn. Nowadays, this word is used to mean "century". There are three interpretations of the word in this hadith:

1. One hundred years. There are several hadith narrated in which the Prophet (sas) said that someone will reach "qarn" and then other reports state that that person lived to 100 years. There are differences as to this last point, however.
2. The people of a particular time who were together in a certain affair - such as under a particular prophet or leader.
3. That the "qarn" of the Prophet (sas) is the Companions, the next one is the Followers (taabi'een) and the third one is their Followers.