Imam Bukhari’s (May Allah shower His Mercy on him) opinion about not remaining a believer
Abu ‘Abdullah (i.e. Imam Bukhari) (May Allah shower His Mercy on him) has said that such a person does not remain a perfect believer and the radiance of faith is not found in that person. [These are the words of Bukhari]
Three signs of a hypocrite
[57/7]-It is narrated on the authority of Hadhrat Abu Hurairah (May Allah be well pleased with him), he says that the Holy Prophet (Sallallahu alaihi wa sallam) said: A hypocrite has 3 signs (Muslim adds to this:) even though he fasts, offers Salaat and claims that he is a Muslim.
Bukhari and Muslim unanimously relate: (1) When he talks, he lies, (2) when he makes a promise, he breaks it and (3) when is entrusted with something, he embezzles it. These are the 3 signs of a hypocrite.
Bukhari and Muslim have unanimously related this Hadith.
The person with these 4 things is a hypocrite for sure
[58/8]-It is narrated on the authority of Hadhrat ‘Abdullah bin ‘Amr (May Allah be well pleased with him), he said that the Holy Prophet (Sallallahu alaihi wa sallam) said: The person who has (all) these 4 things is an absolute hypocrite and the person who has any one of them has a trait of hypocrisy unless and until that person does not stop doing so: (1) When he is entrusted with something, he embezzles it; (2) when he talks, he lies; (3) when he makes a promise, he breaches it and (4) when he quarrels, he abuses.
Bukhari and Muslim have unanimously related this Hadith.
Similitude of a hypocrite
[59/9]-It is narrated on the authority of Hadhrat ‘Abdullah bin ‘Umar that the Holy Prophet (Sallallahu alaihi wa sallam) said: The hypocrite is like a goat which wanders between 2 herds, sometimes hither, sometimes thither.
Muslim has related this Hadith.