The first thing you will lose of your religion is humility (khushu)

It is narrated from Abd al-Aziz, the nephew of Sayyiduna Hudhayfah (may Allah be pleased with him), that Sayyiduna Hudhayfah (may Allah be pleased with him) said: "The first thing of your religion that you will lose is humility (khushu'), and the last thing of your religion that you will lose is the prayer. The handholds of Islam will certainly be broken one by one, to the point that women will pray even while menstruating. You will certainly follow the path of those before you exactly, as one feather (of an arrow) matches another and as one sandal matches another; you will not stray from their path, nor will you be diverted from it, until only two sects remain out of many sects. One of them will say: 'What is the matter with these five prayers! Those before us surely went astray; Allah Almighty has only said: "And establish the prayer at the two ends of the day and in some hours of the night." [Surah Hud: 114]' So they will pray only three prayers. And the other sect will say: 'We believe in Allah just as the angels believe; there is neither a disbeliever nor a hypocrite among us.' So it is a right upon Allah that He gather both of these (misguided sects) with the Dajjal."
This hadith has an authentic (sahih) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Abu al-Tufayl that he said: Amr bin Sulay' and I went to Sayyiduna Hudhayfah bin al-Yaman (may Allah be pleased with him) while two rows of people were with him. We said: "O Hudhayfah! You attained what we could not attain, you came to know what we could not know, and you heard what we could not hear; so tell us something by which Allah may benefit us." He said: "If I were to tell you everything I have heard, you would not wait with me even until nightfall (out of astonishment and displeasure)." We said: "That is not what we intend; rather, tell us something by which Allah may benefit us." He said: "If I were to tell you that the mother of one of you (the Mother of the Believers) would fight with a great army until she wields the sword, you would not believe me." We said: "We are not asking about this; tell us something beneficial." Then Hudhayfah (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) say: "This tribe of Mudar will continue to kill the righteous servants of Allah, destroying and annihilating them, until Allah sends His armies against them, which will kill them in such a way that they will not be able to protect even the lower end of a watercourse (or a place of refuge)." Amr bin Sulay' said (in amazement): "May his mother lose him! Have you warned the people only of the evil of the tribe of Mudar?" Hudhayfah (may Allah be pleased with him) said: "Are you not from the tribe of Muharib Khasafah?" He said: "Certainly." So Hudhayfah (may Allah be pleased with him) said: "Then when you see that the tribe of Qays has taken control of Sham, take your precautions."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.