Death on Friday, complete awareness at the time of death, the colour of the face being bright at the time of death—these cannot be considered as sure signs of faith because even atheists die on this day, fully conscious, faces bright. The fact of the matter is that some diseases like tuberculosis are actually such that those suffering from them remain conscious till the very end; in fact, some forms of the plague are also of this very nature.
I have personally witnessed instances when a patient was made to recite the Kalimah [creed of Islam] and Surah Ya Sin [Chapter 36 of the Holy Quran] was read out to him [because death was presumed nigh], but thereafter he survived and returned to his previous sinful life. This indicates that he had not truly repented, or else he would not have behaved in this way. Actually, the recitation of the Kalimah at such a time does not mean one has come to believe. This type of declaration of faith at a time of fear is not accepted.1
1 Badr, vol. 7, no. 3, p. 3, dated 16 January 1908