[1] (V.14:27) i.e. immediately after their death (in their graves, etc.), when the angels (Munkar and Nakîr ) will ask them three questions: As to: (1) Who is your Lord? (2) What is your religion? and (3) What do you say about this man (Prophet Muhammad صلى الله عليه وسلم) who was sent to you? The believers will give the correct answers, i.e. (1) My Lord is Allâh; (2) My religion is Islâm; and (3) This man Muhammad صلى الله عليه وسلم is Allâh’s Messenger, and he came to us with clear signs and we believed in him, - while the wrong-doers who believed not in the Message of Prophet Muhammad صلى الله عليه وسلم will not be able to answer these questions. [See Tafsir Ibn Kathir].
[2] (V.14:27) See the footnotes of (V.3:85) and (V.6:93).