If this kalimah is pronounced with truthfulness and sincerity and its essential requirements are acted upon, both inwardly and outwardly, then its effects upon both the individual and the society will indeed be praiseworthy.
From the most important of these effects are:
1- Having a united word which results in the Muslims acquiring strength and achieving victory over their enemies. This is because they submit to one Religion and to a single creed (‘aqeedah), as Allaah the Most High said:
“And hold fast altogether to the rope of Allaah and do not become divided.” [Soorah Aal-’Imraan 3:101].
And Allaah the Most High said:
“He it is that has strengthened you with His help and with the Believers. And moreover, He has united their hearts with love and affection. If you had spent all that is in the earth, you could not have united their hearts with love and affection. However, Allaah has united them. Indeed Allaah is the All-Mighty, All-Wise.” [Soorah al-Anfaal 8:62-63].
And differing in the creed is a cause for divisions, disputes and hostility - as Allaah the Exalted said:
“Indeed those who split up their religion and become sects, you have no concern with them in the least.” [Soorah al-An’aam 6:159].
And Allaah the Most High said: “But people have cut off
their affair of unity between themselves, into sects; each party rejoices in that which is with itself.” [Soorah al-Mu’minoon 23:53].
So people cannot be united except upon a common creed of faith (eemaan) and tawheed; which is the implication of laa ilaaha illallaah - and this can be seen in the condition of the Arabs before and after Islaam.
2 - The prevalence of peace and tranquility in a society that professes tawheed and submits to the requirements of laa ilaaha illallaah. This is because every individual will take only that which Allaah has made lawful and leave that which He has prohibited, doing so in response with what the kalimah requires of him. So he will refrain from aggression, injustice and transgression and in its place will be co-operation, love and allegiance for the sake of Allaah; acting upon Allaah, the Most High’s, saying: “Indeed the Believers are but brothers.” [Soorah alHujuraat 4 9:10]
This is clearly reflected in the condition of the Arabs before they submitted to this kalimah, and after they submitted to it.
Before they submitted to it they used to be enemies, slaughtering one another, boasting about killing, looting and plundering. But when they submitted to it, they became brothers who had mutual love for one another. Allaah the Exalted said:
“Muhammad is the Messenger of Allaah; and those with him are harsh against the unbelievers, but kind and merciful to each other.” [Soorah al-Fath 48:29].
And Allaah the Most High said:
“And remember the favor of Allaah upon you, for you were once enemies to one another but He joined your hearts together in love, so that by His Grace you became brothers.” [Soorah Aal-’Imraan 3:103].