( وَإِن تُطِعْ أَكْثَرَ مَن فِي الْأَرْضِ يُضِلُّوكَ عَن سَبِيلِ اللَّهِ ) (And if you obey most of those upon the earth, they will mislead you from the way of Allah): There are many of those who try to mislead people. The speech here is directed to the nation of Prophet Mohammad (saws), because the Prophet (saws) obeyed only Allah the Almighty (swt). When Allah (swt) says:

( وَإِن تُطِعْ أَكْثَرَ مَن فِي الْأَرْضِ يُضِلُّوك ) (And if you obey most of those upon the earth, they will mislead you)

      or:

( يَا أَيُّهَا النَّبِيُّ اتَّقِ اللَّهَ وَلَا تُطِعِ الْكَافِرِينَ وَالْمُنَافِقِينَ )

(O Prophet, fear Allah and do not obey the disbelievers and the hypocrites) (Al-Ahzaab:1)

This is an order for the nation of the Prophet (saws), because he (saws) is the master of the pious. Allah (swt) here states that if you follow most people on this earth, they will lead you astray and misguide you from the straight path of Allah (swt) because they only follow assumptions and they are only falsifying.