Praise be to Allah.

We ask Allah to make us and you steadfast in adherence to His religion, and to ward off from us the plots of the Shaytaan, for he is a clear enemy who seeks to lead people astray. You should note that enjoining what is good and forbidding what is evil is one of the characteristics of the believers. Allah, may He be exalted, says (interpretation of the meaning):

“The believers, men and women, are Awliya (helpers, supporters, friends, protectors) of one another, they enjoin (on the people) Al-Maroof (i.e. Islamic Monotheism and all that Islam orders one to do), and forbid (people) from Al-Munkar (i.e. polytheism and disbelief of all kinds, and all that Islam has forbidden)”

[at-Tawbah 9:71]. 

But the one who wants to enjoin what is good and forbid what is evil should not let his actions contradict his words; rather he should enjoin what is good and do it, and he should forbid what is evil and avoid it. Allah, may He be exalted, says (interpretation of the meaning):

“O you who believe! Why do you say that which you do not do?

Most hateful it is with Allah that you say that which you do not do”

[as-Saff 61:2-3]. 

And Shu ‘ayb (peace be upon him) said:

“I wish not, in contradiction to you, to do that which I forbid you”

[Hood 11:88]. 

Al-Bukhaari (3267) and Muslim (2989) narrated that Usaamah ibn Zayd (may Allah be pleased with him) said: I heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “A man will be brought on the Day of Resurrection and thrown into the Fire; his intestines will spill forth in the Fire and he will go around as a donkey goes around the millstone. The people of Hell will gather around him and will say: O So and so, what is the matter with you? Did you not enjoin what is good and forbid what is evil? He will say: Yes, but I used to enjoin good and not do it, and I used to forbid evil and do it.” 

Ibn Baaz (may Allah have mercy on him) said:  

One of the qualities and characteristics that the daa‘iyah (the one who calls others to Allah) should – indeed must – have is that he must act upon what he calls people to and he should be a good example of what he is promoting. He should not be one of those who call people to something then fail to do it themselves, or who tell people not to do something, then do it. That is the state of the losers; we seek refuge with Allah from that. As for the believers who will succeed, they call people to the truth and act in accordance with it, striving and hastening to attain it, and keeping away from that which they tell others not to do.

End quote from Majmoo‘ Fataawa Ibn Baaz, 1/346 

Ibn ‘Uthaymeen (may Allah have mercy on him) said: 

Part of the etiquette of enjoining what is good and forbidding what is evil is that one should be the first to obey the commands and the first to avoid what is forbidden.

End quote from Sharh Riyaadh as-Saaliheen, p. 202 

If a person exhorts his brother concerning a sin that he himself has fallen into, although this is something that is not befitting for the Muslim, it does not come under the heading of hypocrisy or showing off. 

The Standing Committee was asked: 

If I exhort my brothers and warn them against certain sins, but I myself fall into those sins, am I regarded as a hypocrite? 

The Committee replied: You have to repent from sins and exhort your brothers to avoid them. It is not permissible for you to commit sins and fail to advise your brothers, because this is combining two sins. You have to repent to Allah from that whilst still advising your brothers. That is not hypocrisy, but you have fallen into something for which Allah criticises those who do it, as He, may He be glorified, says (interpretation of the meaning):

“O you who believe! Why do you say that which you do not do?

Most hateful it is with Allah that you say that which you do not do”

[as-Saff 61:2-3] 

“Enjoin you Al-Birr (piety and righteousness and each and every act of obedience to Allah) on the people and you forget (to practise it) yourselves, while you recite the Scripture! Have you then no sense?”

[al-Baqarah 2:44]. 

End quote from Fataawa al-Lajnah ad-Daa’imah, 12/268 

Based on that, you should carry on enjoining what is good and forbidding what is evil, and do not let the fact that you have fallen into the sin that you are telling others not to do stop you from doing that. But you have to strive hard to give it up and to avoid all sins, because the bad consequences, in this world and in the Hereafter, of disobeying Allah and His Messenger will be borne by the one who does that. You should also note that if it is obligatory for everyone to stop what he is doing of sin, this is even more important in the case of one who seeks to enjoin people to do what is good and forbid them to do what is bad, because such an attitude is regarded as blameworthy and shameful before Allah, as stated above. 

Undoubtedly your taking stock of yourself in this manner is something for which you are to be commended, so persist in that and think positively of Allah; do not despair of His mercy, and strive hard to give up that sin. 

You should note that it is important to strive hard against one’s nafs (jihad an-nafs) so as to rid it of any traces of showing off, and try to acquire sincerity towards Allah in everything one does. But to think that one is showing off, then trying to ward off the Shaytaan, who put this idea in one’s mind, does not come under the heading of righteous deeds, because one of the ways in which the Shaytaan tries to make the son of Adam give up striving is by making him imagine that he is showing off. So you should not pay any attention to that and you should try to ignore it. 

Ibn al-Mubaarak narrated in az-Zuhd (p. 12) that al-Haarith ibn Qays said: If you want to do something good, then do not put it off until tomorrow; if you are doing something pertaining to the Hereafter, then continue as long as you can; if you are praying and the Shaytaan tells you that you are showing off (by making it long), then make it longer.

Az-Zuhd by Ibn al-Mubaarak, p. 12 

Ibn Muflih (may Allah have mercy on him) said: 

One of the things that happen to man, is that when he wants to do an act of obedience, something happens to him that make him refrain from doing it for fear of showing off. What he should do is pay no attention to that. If a person does what Allah, may He be glorified and exalted, has commanded him and encouraged him to do, he should seek the help of Allah and put his trust in Him to enable him to do it in the prescribed manner. 

Shaykh Muhyi ad-Deen an-Nawawi (may Allah have mercy on him) said: You should not refrain from remembering Allah verbally or in one’s heart for fear of being thought of as showing off; rather you should remember Him in both ways, seeking thereby the Countenance of Allah, may He be glorified and exalted.

End quote from al-Adaab ash-Shar‘iyyah, 1/333 

You have to be focused and steadfast, and not pay any attention to the whispers (waswaas) of the Shaytaan. Every time the Shaytaan comes to you to instil in your mind the idea that you are showing off, carry on with the righteous deed and hasten to do it with no delay, and that waswaas will disappear in sha Allah, because when the Shaytaan sees that every time he tries to make a person think that he is showing off, that person carries on doing the righteous deed and does not stop, he gives up on him and stops whispering to him, because it is having the opposite effect. 

But if he whispers to him and he pays attention to this waswaas, he will do it even more until he diverts him from that righteous deed. 

And Allah knows best.