Belief in Techiyas Hameisim based on Scripture:
Any Jew who does not believe that the basis of Techias Hameisim is found in the Torah is considered a Heretic. This means that even if one believes that the resurrection will occur, but denies that this belief is hinted in the verses of the Torah of which the Sages expound on, then he is considered a heretic. As if he states that the resurrection is not a Torah belief, then what relevance does his belief have, as from where does he know that his belief is true. He is therefore considered a complete heretic. [Seemingly, this means that if one believes in the resurrection as a personal belief, and not as a belief that is preached by Hashem in His Torah or as a belief that is backed by Jewish tradition to Sinai, then he is a heretic, as it is similar to one who denies that a Mitzvah came from Hashem. If however one believes in the resurrection due to the oral tradition from Sinai, then even if he is not aware or does not believe in any hints in the Torah, he is not considered a heretic. Nonetheless, he is still doing a grave sin in not believing in the words of the Sages that teach that the verses hint to the resurrection.]
Are the scriptural hints considered a true proof? The verses in the Torah of which the Sages expound to teach about Techias Hameisim are not conclusive proof of the fact that the Torah holds that Techias Hameisim will occur, as in truth all these verses can be interpreted differently. Rather, it is the age old tradition of the Jewish people handed from generation to generation until Moshe Rabbeinu that is the driving force behind the belief in the resurrection, and the verses merely serve as a hint towards this belief. Furthermore, the tradition teaches us that the true understanding of the verse is that it refers to the resurrection, and negates the other interpretations.
 Mishneh Sanhedrin 90a
 Rashi ibid
Other opinions: The Yad Rameh ibid writes that in his version of the Mishneh it simply states “These do not have a portion in the world to come; one who denies Techiyas Hameisim and says the dead will not be resurrected at all” and not one who denies its source in the Torah. He then however quotes the version of Rashi brought above. The Yerushalmi 10/1 in its quote of the Mishneh omits the words “from the Torah”. The Beir Sheva ibid questions the above opinion of Rashi and brings proofs that a person is not a heretic if he believes in Techias Hameisim, irrelevant to his specific belief in a verse. He thus concludes that there must be misquote from Rashi and certainly a wayward student printed the words in the commentary of Rashi.
 Beir Sheva ibid; Implication of Rashba 9; and so is implied to also be the opinion of Rashi ibid [and hence there is no dispute between them] as Rashi states “As if he states that the resurrection is not a Torah belief, then what relevance does his belief have, as from where does he know that his belief is true.” Now, if one believes in the resurrection due to the Oral tradition of Sinai, then certainly he has basis for his belief and cannot be considered a heretic, hence one must say Rashi refers to a person that denies completely the Torah basis for ressurection, both in the written and Oral Torah.
 Shut Rashba 9