The believers in the beginning were now outnumbered by a people who either ignored the Nabi (s) or fought the Nabi (s). Imam Ali (a) decided not to go to war, not because, he didn't think he would win or lose, but because it would be seen forever as greed for power when majority didn't want Ali (a) in power. The believers did of course want to help but some of them were apathetic in start, but Fatima (a) reminded them, and they went out to revive the Sunnah peacefully.
Why do you think Uthman got overthrown and people ran to Ali (a). Yes, part of it was corruption of governors, but why to Ali (a) this time.
Endless war of this was not the solution. There probably would be no hadith in praise of Imam Ali (a) left in his opponents, if he fought Abu Bakr. So he spared the believers fighting and they were very few, and the original followers of Mohammad (s) and Ali (a) outnumbered by people clueless about the Sunnah and Quran they spent the most of 23 blessed years of Nubuwa and Quranic tanzil fighting Mohammad (s) in this regard.
I was wiser to wait, and he even warned them, it would be better for him to remain an advisor for them, and power is not necessary, you can give it to someone else. But they all swore to him they would be sincere in their oaths. Then some broke it and Mauwiya did what he did, and used the propaganda of the hypocrites to make it into an issue of the initial division between Abu Bakr and Ali (a). Although there was this religion dispute about successorship among people, and some people understood Quran and others didn't, followers of Ali (a) were of those who can understand Wilayah of Ali (a) and those who despite sermons of Ali (a) and clarification of the Sunnah from the companions, couldn't understand Quran due to their unjust and oppressive heedless nature.
The original companions as in those who emigrated from Mecca and the ones who were sincerely meeting and then invited Mohammad and Ali (peace be upon them both and their family) to come to Yathrib which then became Madinatal Munuwara were outnumbered.
The original believers were now outnumbered by people who God forgave like the brothers of Joseph but no way are these people immune to turning back on their religion. Perhaps if the will of the Prophet was accepted without division and dispute and he was not poisoned and what occurred didn't occur in that regard, perhaps, mental clarity would have been everlasting till this day.
And Quran shows from the start, in Yathrib, there was always a people who disagreed with giving Mohammad (s) refuge but pretended to have faith. It's not impossible this occurred with some of those who migrated from Mecca to sabotage as this an ancient war between God's forces and believers against Gog and Magog and those who they deceive.
In 4th chapter there is also an allusion to Gog (the one who Satan is the Qareen, not sends a Qareen but is the Qareen) and spending wealth to show off to people before the talk of Christian and Jewish scholars, and the talk of Ahlulbayt of Abraham and Ulil-Amr.
Gog is not out in the open today nor his followers (magog), but he does what he does. And Suratal Tahreem shows a division about to take place in which Aisha and Hafsa did the right decision then after a wrong decision.
The point, is all this stuff is volatile. Messengers after Moses' did their best, but maybe, followers didn't help enough or enemies were just to sly and deceiving in how they corrupted the Torah and place of Aaron and his family.
God is the best judge in all this, but, the issue of interpretation of holy scripture is always the first dispute. Usually it ends up that the messages are left and then as a result, the original scripture get's distorted.
Somehow the reminder remains and the book, no falsehood comes to it, and we are lucky in this regard that God planned and made the Quran the way it is.
Try to appreciate it and the excuse it gave people to oppose the family of Mohammad like Yacoub gave his sons with the wolf, so they one day return.
Otherwise there be hardly any followers of Quran today and no one would even know of Mohammad and his family. God has wisdom in his ways. Trust the Quran to clarify and guide, and give a chance of the ahadith of Ahlulbayt of his Nabi to guide you and compliment it and give you insights to it.
This all I ask.