Does the Shaytaan call the dying person to become a Jew or Christian? And what is meant by the “trials of death”?

Is it true that one of the trials of the grave involves the devils appearing in the form of one's parents and saying “We followed Judaism or Christianity and Allaah admitted us to Paradise”? Does that happen before Munkar and Nakeer come down?.

Praise be to Allaah.
There is no evidence for this from the Qur’aan or Sunnah, rather this is what some scholars say, but that does not happen in the grave, rather it happens when a person is dying, before the soul is taken. Some scholars stated that this comes under the heading of “the trials of life”. 
Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said: 
The presenting of other religions to a person at the time of death does not happen to everyone, but we cannot say that it does not happen to anyone. Rather some people may not have other religions presented to them, and some do have them presented to them. All of that is part of the trials of life from which the Messenger commanded us to seek refuge when praying. At the time of death, the Shaytaan is most keen to tempt the sons of Adam. End quote from al-Ikhtiyaaraat, p. 85. 
The Shaytaan remains eager to tempt a person so long as his soul is still in his body, so he comes to him, whispers to him and makes falsehood appear attractive to him. 
It was narrated from Abu Sa’eed al-Khudri (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Iblees said: ‘By Your glory, I will not stop tempting Your slaves so long as their souls are in their bodies.’ [Allaah] said: ‘By My Glory and Majesty, I will continue to forgive them so long as they ask Me for forgiveness.’”
Narrated by Ahmad, 10974; classed as hasan by al-Albaani in Saheeh al-Targheeb, 1617. 
The Prophet (peace and blessings of Allaah be upon him) used to seek refuge with Allaah from the “trials of life and death,” and he encouraged worshippers to seek refuge from them before saying the salaam at the end of the prayer. 
It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “When one of you has finished the final tashahhud, let him seek refuge with Allaah from four things: from the torment of Hell, from the torment of the grave, from the trials of life and death, and from the evil of the Dajjaal.” Narrated by al-Bukhaari, 1311; Muslim, 588. 
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) said: 
The words “from the trials of life and death” come after the words, “from the torment of Hell.” What is meant by trials (fitnah) here is the testing of a man with regard to his religious commitment, during his life and after his death. The trials of life are great and intense, and very few pass the test except those whom Allaah wills. They revolve around two things: 
1-     Doubts
2-     Desires 
As for doubts, man is faced with doubts with regard to his knowledge, so he becomes confused with regard to what is true and what is false, and he sees falsehood as truth and truth as falsehood. If he sees truth as falsehood he will avoid it, and if he sees falsehood as truth he will follow it.  
As for desires, he is faced with them with regard to his will. Because of his desires, he wants something that is forbidden to him. This is a serious temptation (fitnah); how many are those who see riba as opportunity and indulge in it; how many are those who see deceiving people as cleverness in buying and selling, and indulge in deceit; how many are those who see looking at women as pleasure, enjoyment and freedom, and they give free rein to their gaze; how many are those who drink alcohol and it as pleasure and relaxation; how many are those who watch entertainment and listen to music, regarding it as an art to be studied, for which certificates and awards are to be given. 
As for the trials of death, the scholars differed concerning them and there are two views: 
The first view is that the “trials of death” refers to the questioning by the two angels of the deceased in his grave, about his Lord, his religion and his Prophet, because the Prophet (peace and blessings of Allaah be upon him) said: “It has been revealed to me that you will be put to trial in your graves like or almost like the tribulation of the Dajjaal.” As for the one whose faith is sincere, it will be easy for him to answer. 
When he is asked: Who is your Lord? He will say: My Lord is Allaah. 
Who is your Prophet? He will say: My Prophet is Muhammad. 
What is your religion? He will say: My religion is Islam – it will be very easy for him. 
As for anyone else – Allaah forbid – when he is asked he will say, Oh, oh, I do not know; I heard the people saying something so I said it too. 
Think about it, how he will say, “Oh, oh,” as if he used to know something but forgot it. What greater loss can there be than something that you learned then forgot, because the one who is ignorant does not gain anything, but the one who forgot gained something and then lost it. The result will be that he will say: I do not know who is my Lord, what my religion is or who my Prophet is. This is a great fitnah; I ask Allaah to save me and you from it. In fact it depends on what is in the heart. If the heart truly believes, and sees matters of the unseen as if with the eye, then he will answer with ease, but if it is the opposite, then his answer will be the opposite. 
The second view is that what is meant by “the trials of death” is what happens at the time of death, in the last moments of life. This was mentioned as such – even though it is one of the trials of life – because of its seriousness and importance, just as the fitnah of the Dajjaal is also mentioned even though it is one of the trials of life, but it is also one of the trials of death because it happens close to death, and it is singled out for mention because it is the worst that can happen. That is because when a person is dying and bidding farewell, his destiny will be either happiness or doom. The Messenger (peace and blessings of Allaah be upon him) said: “One of you may do the deeds of the people of Paradise until, when there is nothing between him and it but a cubit, the decree overtakes him and he does a deed of the people of Hell.” So the fitnah is great indeed. 
The Shaytaan is at his most eager to tempt the son of Adam at this moment, and the one who is truly protected is the one whom Allaah protects. He comes to him at this crucial moment which no one can imagine but the one to whom it happens. Allaah says (interpretation of the meaning): 
“Nay, when (the soul) reaches to the collarbone (i.e. up to the throat in its exit),
27. And it will be said: Who can cure him (and save him from death)?
28. And he (the dying person) will conclude that it was (the time) of parting (death);
29. And one leg will be joined with another leg (shrouded).
30. The drive will be on that Day to your Lord (Allaah)!”
[al-Qiyaamah 75:26-30] 
It is a critical situation, when a person is weak, lacking in strength and willpower, feeling anxious, and the shaytaan comes to him to tempt him, to such a point that it is as the scholars said: he may present the Jewish, Christian and Islamic religions to a person, appearing the form of his parents who present the Jewish, Christian and Islamic religions to him and encourage him to follow Judaism or Christianity. The Shaytaan may take on the form of anyone except the Prophet (peace and blessings of Allaah be upon him), and this is the greatest of trials.  

But this – praise be to Allaah – does not happen to everyone, as was stated by Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him). Even if the Shaytaan is not able to gain control over a person to such a degree, there is still fear for him. 
It was said that when Imam Ahmad was dying, he could be heard saying, “Not yet, not yet.” When he came to, he was asked about that and he said: The Shaytaan was biting his fingertips and saying, “You got away from me, O Ahmad.” He was biting his fingers out of regret that he had not deceived Imam Ahmad, and Ahmad said to him, “Not yet, not yet” – i.e., the soul has not yet departed. So long as the soul is in the body, anything is possible. “Our Lord! Let not our hearts deviate (from the truth) after You have guided us” [Aal ‘Imraan 3:8]. In this situation fitnah is great indeed. Hence the Prophet (peace and blessings of Allaah be upon him) said: “… from the trials of life and death.” 
Conclusion: There are two interpretations of what is meant by the trials of death: 
1-     It is the trials and temptations that happen at the time of death.
2-     That they come after death, when the two angels question a man about his Lord, his religion and his Prophet. 
There is no reason why we should not say that it includes both. It may refer both to the trials that come before death and at the time of death, because these are the greatest tribulations that a man ever faces. Mention is also made of what is feared of a bad end if Allaah does not save a person from this tribulation. 
Based on this, the one who prays for refuge from the trials of death should bear both situations in mind. 
Al-Sharh al-Mumti’, 3/185-188 
And Allaah knows best..