Ref. No. 1207/42-505
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
ان بنی اسرائیل تفرقت علی ثنتین وسبعین ملۃ وتفترق امتی علی ثلاث وسبعین ملۃ کلھم فی النار الا ملۃ واحدۃ قالوا من ھی یا رسول اللہ ﷺ قال ماانا علیہ واصحابی۔۔
This hadith is saheeh. In order to avail salvation in the Akhirat, it is necessary to follow the way of the companions of the Prophet (saws) in belief, deeds and words. And those who have deviated from this way, such as Shiites, Kharijites, Qadriyas, Jabriyas, Mu'tazilites, etc are included in 72 sects who have gone astray. Therefore, it is not correct for the questioner to say that I am only a Muslim, not a Shia or a Sunni. Instead, he should try to enter the only sect which is destined to have salvation as promised in hadith.
And Allah knows best
Darul Uloom Waqf Deoband