What Are the Conditions of La Ilaha Illa-Allah?
Question

Can you please explain the conditions of La ilaha illa-Allah (knowledge, certainty, etc.), and tell us the rulings on one who does not attain them and one who is ignorant of the meaning of La ilaha illa-Allah?
Praise be to Allah.The conditions of La ilaha illa-Allah 
Shaykh Hafiz al-Hukmi said in his poem Sullam al-Wusul: 
“Knowledge, certainty, submission and following. So listen to what I say.
Truthfulness, sincerity and love. May Allah help you to do that which He loves.”

The first condition is knowledge, in the sense of negating what is negated in the Shahadah and affirming what is affirmed therein – as opposed to being ignorant of that.

 Allah says (interpretation of the meanings):
 “So know (O Muhammad) that La ilaha illa-Allah (none has the right to be worshipped but Allah)…” [Muhammad 47:19]
 “except for those who bear witness to the truth knowingly” –  i.e., that there is no god except Allah (La ilaha illa-Allah ) – “and they know” – in their hearts the meaning of the words that they utter with their lips. [al-Zukhruf 43:86]
 It is narrated in al-Sahih from ‘Uthman (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: “Whoever dies knowing that there is no god except Allah will enter Paradise.”

The second condition is certainty, in the sense that the one who says these words is absolutely certain of their meaning. Faith is not sufficient unless it is based on certain knowledge with no element of speculation, let alone doubt. Allah says (interpretation of the meaning): 

“Only those are the believers who have believed in Allah and His Messenger, and afterward doubt not but strive with their wealth and their lives for the Cause of Allah. Those! They are the truthful” [al-Hujurat 49:15] 
The sincerity of their faith in Allah and His Messenger is conditional upon there being no element of doubt therein, As for the doubter, he is one of the hypocrites. In al-Sahih, it is narrated that Abu Hurayrah said: “The Messenger of Allah (peace and blessings of Allah be upon him) said: ‘Bear witness that there is no god except Allah and that I am the Messenger of Allah, for no person meets Allah with these two, not doubting in them, but he will enter Paradise.’” According to another report: “No person meets Allah with these two, not doubting in them, and is denied Paradise.” 
And it was also narrated from Abu Hurayrah in a lengthy hadith that the Prophet (peace and blessings of Allah be upon him) sent him and said, “Whoever you meet behind this wall who bears witness that there is no god except Allah, believing in it with certainty in his heart, then give him the glad tidings of Paradise.”
Thus we see that a person’s entering Paradise for saying these words is conditional upon his believing in them with certainty in his heart, with no element of doubt. If this condition is not met the target is not met. 

The third condition is acceptance and submission to what these words imply, both in one's heart as well as verbally. Allah has told us the stories of those who came before, who were saved by their acceptance of these words from the punishment of those who had rejected them. Allah says (interpretation of the meaning):

 “(It will be said to the angels): ‘Assemble those who did wrong, together with their companions (from the devils) and what they used to worship,
Instead of Allah, and lead them on to the way of flaming Fire (Hell);
But stop them, verily, they are to be questioned.
What is the matter with you? Why do you not help one another (as you used to do in the world)?’
Nay, but that Day they shall surrender.
And they will turn to one another and question one another.
They will say: ‘It was you who used to come to us from the right side (i.e., from the right side of one of us and beautify for us every evil, enjoin on us polytheism, and stop us from the truth, i.e. Islamic Monotheism and from every good deed).’
They will reply: ‘Nay, you yourselves were not believers.
And we had no authority over you. Nay! But you were Taghun (transgressing) people (polytheists, and disbelievers).
So now the Word of our Lord has been justified against us, that we shall certainly (have to) taste (the torment).
So we led you astray because we were ourselves astray.’
Then verily, that Day, they will (all) share in the torment.
Certainly, that is how We deal with Al-Mujrimun (polytheists, sinners, disbelievers, criminals, the disobedient to Allah).
Truly, when it was said to them: La ilaha illa-Allah (none has the right “to be worshipped but Allah),” they puffed themselves up with pride (i.e. denied it).
And (they) said: ‘Are we going to abandon our alihah (gods) for the sake of a mad poet?’” [al-Saffat 37:22-36]
 So Allah has made the reason and cause of their punishment their arrogant refusal to say La ilaha ill-Allah, and their disbelief in the one who brought this message, so that they did not negate what this word negates and they did not affirm what it affirms, rather they said, arrogantly denouncing:
 “‘Has he made the alihah (gods) (all) into One Ilah (God — Allah). Verily, this is a curious thing!’
And the leaders among them went about (saying): ‘Go on, and remain constant to your alihah (gods)! Verily, this is a thing designed (against you)!’”[Sad 38:5] 
So Allah showed them to be liars and threw their words back at them through the words of His Messenger (peace and blessings of Allah be upon him). He said (interpretation of the meaning): 
“Nay! he (Muhammad) has come with the truth (i.e. Allah’s religion — Islamic Monotheism and this Quran) and he confirms the Messengers (before him who brought Allah’s religion — Islamic Monotheism)” [al-Saffat 37:37]
Then He said concerning those who accept it (interpretation of the meaning):
 “Save the chosen slaves of Allah (i.e. the true believers of Islamic Monotheism).
For them there will be a known provision (in Paradise),
Fruits; and they shall be honoured,
In the Gardens of Delight (Paradise)” [al-Saffat 37:40-43] 
In al-Sahih, it is narrated from Abu Musa (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: “The guidance and knowledge with which Allah has sent me is like abundant rain which falls on the land. Some of the land absorbs the water and brings forth much grass and vegetation. And some of (the rain) falls on another part of the land which is like a smooth plain and does not hold the water, so no vegetation grows. That is the likeness of the one who understands the religion of Allah and benefits from that with which Allah has sent me, so he learns and acts, and the likeness of the one who pays no heed and does not accept the guidance of Allah with which I have been sent. 

The fourth condition is following that which is indicated, as opposed to not following it. Allah says (interpretation of the meaning): 

“And whosoever submits his face (himself) to Allah, while he is a Muhsin (good-doer, i.e. performs good deeds totally for Allah’s sake), then he has grasped the most trustworthy handhold” – i.e., La ilaha illa-Allah – “And to Allah return all matters for decision.” [Luqman 31:22] 
What is meant by “submitting one’s face” is following, when one is also a doer of good and a believer in Tawhid. Whoever does not submit his face to Allah and is not a doer of good has not grasped the most trustworthy handhold. This is what is meant by the following verse (interpretation of the meaning): 
“And whoever disbelieves, let not his disbelief grieve you (O Muhammad). To Us is their return, and We shall inform them what they have done…” [Luqman 31:23] 
According to a sahih hadith, the Messenger of Allah (peace and blessings of Allah be upon him) said: “none of you truly believes until his desire is in accordance with that which I have brought.” This is the ultimate meaning of following. 

The fifth condition is truthfulness, as opposed to lying. This means that one says it (La ilaha illa-Allah ) sincerely from the heart, with harmony between what is in the heart and what is said on the lips. Allah says (interpretation of the meaning):

 “Do people think that they will be left alone because they say: ‘We believe,’ and will not be tested.
And We indeed tested those who were before them. And Allah will certainly make (it) known (the truth of) those who are true, and will certainly make (it) known (the falsehood of) those who are liars, (although Allah knows all that before putting them to test)” [al-'Ankabut 29:2-3] 
And He said concerning the hypocrites who spoke these words falsely (interpretation of the meaning): 
“And of mankind, there are some (hypocrites) who say: ‘We believe in Allah and the Last Day,’ while in fact they believe not.
They (think to) deceive Allah and those who believe, while they only deceive themselves, and perceive (it) not!
In their hearts is a disease (of doubt and hypocrisy) and Allah has increased their disease. A painful torment is theirs because they used to tell lies” [al-Baqarah 2:8-10] 
In al-Sahihayn, it is narrated from Mu’adh ibn Jabal (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said, “there is no one who bears witness that there is no god except Allah and that Muhammad is His slave and Messenger, sincerely from the heart, but Allah will make him forbidden for the Fire.” 

The sixth condition is sincerity, which means that actions are free from any element of shirk. Allah says (interpretation of the meaning): 

“Surely, the religion (i.e. the worship and the obedience) is for Allah only [al-Zumar 39:3] 
“Say (O Muhammad): ‘Allah Alone I worship by doing religious deeds sincerely for His sake only’” [al-Zumar 39:14]
 In al-Sahih, it is narrated from Abu Hurayrah that the Prophet (peace and blessings of Allah be upon him) said: “The most deserving of my intercession are those who say La ilaha illa-Allah sincerely from the heart or from the soul.”

The seventh condition is love for this word and for what it implies and indicates, and love for the people who act upon it and adhere to its conditions and hate whoever or whatever goes against it. Allah says (interpretation of the meaning):

 “And of mankind are some who take (for worship) others besides Allah as rivals (to Allah). They love them as they love Allah” [al-Baqarah 2:165]
 Allah tells us that those who believe love Allah more, because they do not associate anything with Him in that love, as is done by those among the mushrikin who claim to love Him but who also take others as rivals to Him whom they love as they love Him. 
In al-Sahihayn, it is narrated from Anas that the Messenger of Allah (peace and blessings of Allah be upon him) said: “No one of you truly believes until I am more beloved to him that his son, his father and all of mankind.”
And Allah knows best.