بسم الله الرحمن الرحيم
A person who believes only on the holy Quran and does not accept the hadith and considers the hadith fabricated he is out of the folk of Islam.
مَّنْ يُطِعِ الرَّسُولَ فَقَدْ أَطَاعَ اللّهَ ً [النساء : 80]
Whoever obeys the Messenger obeys Allah.
It is a fact that the adversaries of Islam have fabricated 3.5 Lakh Hadith and added them to the true hadith. But Almighty Allah created such Ulama who wrote a large number of books on Rijal-e-Hadith and prepared parameters to investigate whether a hadith is true or false. By it one can learn about any hadith whether it is true or false. Hence the saying of the person that it is impossible to find out true hadith is not correct.
Allah knows Best!
Darul Uloom Deoband