Manhaj
The Messenger of Allaah (sallAllaahu 'alayhi wa sallam) clarified the flawless methodology in more than one authentic hadeeth. The Prophet (sallallaahu 'alayhe wa sallam) drew a straight line on the ground one day. Then he drew short lines all around the straight line, on both sides of it. Then he recited Allaah's Statement, Blessed and Exalted:
{And verily this is My Straight Path - follow it! And do not follow the other paths, as they will cause you to break away from My Path!} [Surah Al-An'aam 6:153]
After the Prophet (sallAllaahu 'alayhi wa sallam) read the verse, he ran his finger along the straight path and said:
"This is the Path of Allaah, and these paths on its sides, the sides of the straight path, there is a Shaytaan at the head of every path, calling the people to it." [Authentic hadeeth collected by Ahmad and Ad-Daarimee] SOURCE
{And verily this is My Straight Path - follow it! And do not follow the other paths, as they will cause you to break away from My Path!} [Surah Al-An'aam 6:153]
After the Prophet (sallAllaahu 'alayhi wa sallam) read the verse, he ran his finger along the straight path and said:
"This is the Path of Allaah, and these paths on its sides, the sides of the straight path, there is a Shaytaan at the head of every path, calling the people to it." [Authentic hadeeth collected by Ahmad and Ad-Daarimee] SOURCE