I seek refuge in God from Satan the rejected.
In the name of God, Most Gracious, Most Merciful.
In Quran we are commanded not to divide ourselves into sects. Thus dividing
our religion into sects is against God's command. Those who divide into sects
are termed as idol worshippers, and not members of God's religion.
[6:159] Those who divide themselves into sects do not belong with you. Their judgment rests with GOD, then He will inform them of everything they had done.
[30:31] You shall submit to Him, reverence Him, observe
the Contact Prayers (Salat), and - whatever you do - do not ever fall into idol
worship.
[30:32] (Do not fall in idol worship,) like those who divide their religion
into sects; each party rejoicing with what they have.
[42:14] Ironically, they broke up into sects only after the knowledge had come to them, due to jealousy and resentment among themselves. If it were not for a predetermined decision from your Lord to respite them for a definite interim, they would have been judged immediately. Indeed, the later generations who inherited the scripture are full of doubts.
We learn from above that dividing religion into sects is akin to falling into idol worship, an unforgivable sin (if maintained to death). It doesn't matter what a person calls his or her sect, it is not authorized by God. God condemns all sects.
We are Submitters (Muslims in Arabic) to God alone. We follow God's words in His Final Testament to us, Quran and accept all of God's scriptures. We believe that Quran is perfect and fully detailed as God says, and that we should not follow any other sources besides it. We also believe that God alone is worthy of worship, and that we have to abandon all kinds of idols.
[41:33] Who can utter better words than one who invites to GOD, works righteousness, and says, "I am one of the submitters"?
What we need to ask ourselves is why there are several religions and sects to begin with? What sets them apart? If all worshipped God alone, and uphold God's words, wouldn't they all be united and not differ at all? What sets these different sects apart is mainly their the human factors, and the upholding of various sources besides God's words. For example – traditional muslims uphold a multitude of Hadith and Sunna besides the Quran. In addition to that, some follow writings of various scholars and religious leaders, that go against God's words, without any kind of proof from God.
Again, if we stop to think about Abraham, Moses, Jesus or Muhammad, we realize they were never a member of any sect. They were simply submitters, devoted to God Alone. These sects were formed much after these prophets of God had departed, and are in direct contradiction with God's teachings mentioned above.
Thus, a person who abides by the Quran says "I am a Submitter (Muslim)", not "I am Shia", nor "I am Sunni", or anything else (2:128, 132, 133, 136; 3:52, 64, 67, 84, 102; 5:111; 41:33; 46:15, and more.) People who do so, also forget that Abraham was the original messenger of Submission (Islam), and not Muhammad. If we follow the religion of Abraham, as God commands us to do (3:95), we will call ourselves what Abraham called himself, i.e. a submitter.
[2:127] As Abraham raised the foundations of the shrine,
together with Ismail (they prayed): "Our Lord, accept this from us. You
are the Hearer, the Omniscient.
[2:128] "Our Lord, make us submitters to You, and from
our descendants let there be a community of submitters to You. Teach us the
rites of our religion, and redeem us. You are the Redeemer, Most Merciful.
[2:129] "Our Lord, and raise among them a messenger to recite to them Your
revelations, teach them the scripture and wisdom, and purify them. You are the
Almighty, Most Wise."
[2:130] Who would forsake the religion of Abraham, except one who fools his
own soul? We have chosen him in this world, and in the Hereafter he will be
with the righteous.
[2:131] When his Lord said to him, "Submit," he said, "I submit
to the Lord of the universe."
[2:132] Moreover, Abraham exhorted his children to do the same, and so did Jacob:
"O my children, GOD has pointed out the religion for you; do not
die except as submitters."
[2:133] Had you witnessed Jacob on his death bed; he said to his children, "What
will you worship after I die?" They said, "We will worship your god;
the god of your fathers Abraham, Ismail, and Isaac; the one god. To Him we are
submitters."
May God protect us from creating sects and falling into idol worship.