Allah has sent Muahmmad (salla Allah alayhee wa sallam) with guidance and the true religion to take the people out of darkness into the light and to guide them to that which is good for them in this life and the hereafter. The Prophet (saw) came to a nation known as al-jahiliyah, which is a term that described their time and literally means the days of ignorance. Furthermore the Prophet (saw) transformed this society to become a source of light a source of guidance and a source of positive influence not only in Makkah, not only in Madina, not only in Arabia but the whole entire world.
That impact did not only remain for weeks, or months or years after the Prophet (salla Allah alayhee wa sallam), it rather continued after that and changed the face of the history of humanity until today in the [presence] of the Ummah Know as the Ummah of Muslims. That is why Allah (ta'ala) described this generation (the group that the Prophet (salla Allah alayhee wa sallam) had called to Islam and [who] embraced Islam) as the best nation ever raised for mankind. It was not just a religion. This generation became a role model for every generation that came after them. They are a role model for us to follow in their footsteps. The Prophet (salla Allah alayhee wa sallam) said: "[it is] what I am upon today and my companions." The way to success in this life and salvation in the hereafter is to follow my way and the way of my companions.