Abu Hurairah relates that the Holy Messenger (peace and blessings of Allah be to him) said: All my followers will go to heaven, except those who defied me. He was asked: ‘O Messenger of Allah! Who will be such persons?’ The Holy Messenger (peace and blessings of Allah be to him) elucidated: ‘One who obeys me will enter Paradise and the one who disobeys me defies me (i.e. not enter Paradise).’
(Sahih Bukhari)
Obedience to the Holy Messenger ﷺis part of the Islamic faith. With all other components of Islamic faith, it guarantees the believer a blissful seat in the Paradise.
At the very outset, the Blessed Messenger, with a sense of certainty, gives the glad tidings that all his followers would go to the heaven. But this guarantee is with a precondition that those who claim to be the followers of the Holy Messenger have to follow the teachings and Sunnah of the Holy Messenger – of course in letter and spirit.
When the Blessed Messenger excluded from entering the Heaven those who among his followers would not obey him, the blessed companions who were receiving the message directly asked him who would be thosewho would claim to be his followers and then fail to obey him. Allah’s Messenger ﷺ, in a simpler but more certain way, said that one who would obey him would enter the Paradise and one who would not obey him would not enter this blissful abode.