Praise be to Allah.
Salafiyyah is to follow the way of the Prophet (blessings and peace of Allah be upon him) and his Companions, because they are the ones who came before us (the Salaf) and who advanced ahead of us, so following them is Salafiyyah.
With regard to taking Salafiyyah as a path or methodology which a person follows and regards as misguided those Muslims who differ with him, even if they are following the truth, and taking Salafiyyah as a partisan path is undoubtedly contrary to Salafiyyah. All of the Salaf or early generations called for unity and harmony around the Sunnah of the Messenger (blessings and peace of Allah be upon him) and did not regard as misguided those who differed with them with on the basis of their understanding and interpretation, except when it came to matters of ‘aqeedah or beliefs, because they regarded those who differed with them in these matters as misguided. But with regard to practical issues they were often easy-going.
But some of those who followed the path of Salafiyyah in modern times started to regard as misguided everyone who differed from them, even if that person was correct, and some of them adopted a partisan approach like that of other parties which claimed to belong to the religion of Islam. This is something that is to be denounced and cannot be approved of, and it should be said to these people: Look at the way of the righteous early generation (al-salaf al-saalih), what did they used to do? Look at their way and how open hearted they were in the case of differences in which ijtihaad is justified (and differences of opinion are allowed). They even used to differ concerning major issues, matters of belief and practical issues. You will find some of them, for example, denying that the Messenger (blessings and peace of Allah be upon him) saw his Lord, whereas others say that he did see Him. You will see some of them saying that what will be weighed on the Day of Resurrection is deeds, whereas others will say that it is the books of deeds that will be weighed. You will also see them differing a great deal with regard to matters of fiqh having to do with marriage, shares of inheritance, buying and selling, and other issues. Yet despite all that they did not regard one another as misguided.
Salafiyyah in the sense of being a particular party with its distinguishing characteristics and in which the members regard everyone else as misguided, these people have nothing to do with Salafiyyah at all. As for the Salafiyyah which means following the path of the Salaf in belief, word and deed, in calling for unity and harmony and mutual compassion and love, as the Prophet (blessings and peace of Allah be upon him) said: “The likeness of the believers in their mutual love, mercy and compassion is that of a single body; when one part of it is suffering the rest of the body joins it in fever and staying awake” -- this is the true Salafiyyah. End quote.
Shaykh Muhammad ibn ‘Uthaymeen (may Allah have mercy on him).