How can I overcome waswas? How can I be truly sincere towards Allah?

Firstly:

This devilish waswas (whispers
from the Shaytan) and bad thoughts that cross one’s mind are passing
thoughts that prevent a person from obeying and worshipping Allah, and make
whims and desires fair-seeming to him and encourage him to give in to them. 

Allah will not call a person to
account for these things so long as he does not act upon them or speak of
them. Al-Shaykh Ibn Baz (may Allah have mercy on him) said: 

Whatever may occur to a person’s
mind of bad thoughts, such as if he thinks of zina (fornication or
adultery), stealing, consuming intoxicants and the like, but he does not do
any of these things, then he will be pardoned for that and will not incur
any burden of sin, because the Prophet (blessings and peace of Allah be upon
him) said: “Verily Allah has forgiven my ummah for whatever crosses their
minds, so long as they do not act upon it or speak of it.” Saheeh
(authentic) – agreed upon. 

End quote from Majmoo‘ Fatawa
Ibn Baz (5/424) 

Please also see the answer to
question no.

39684

Secondly: 

It is possible to overcome
waswas and bad thoughts by means of the following: 

·       
Seeking refuge with Allah from the accursed Shaytan, turning sincerely to
Him and beseeching Him a great deal 

Allah, may He be exalted, says
(interpretation of the meaning):

{And if an
evil suggestion comes to you from Satan, then seek refuge in Allah . Indeed,
He is Hearing and Knowing.

Indeed, those
who fear Allah – when an impulse touches them from Satan, they remember
[Him] and at once they have insight.}[al-A‘raf 7:200-201]. 

An example of that is seeking
refuge with Allah from the Shaytan when entering the mosque and when exiting
from it. Abu Dawood (466) narrated from ‘Abdullah ibn ‘Amr (may Allah be
pleased with him) from the Prophet (blessings and peace of Allah be upon
him) that when he entered the mosque he said:
“A‘oodhu
Billah il-‘Azeem wa bi wajhihi’l-kareem wa sultanihi’l-qadeem min al-shaytan
il-rajeem (I seek refuge in Allah, the Mighty and His noble countenance
and His eternal authority from the accursed Shaytan).”
And when he said that, the Shaytan said: “He has been protected from me
for the rest of the day. Classed as saheeh (authentic) by al-Albani in
Saheeh Abi Dawood. 

Ibn Majah (773) narrated from
Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah
(blessings and peace of Allah be upon him) said:
“When any one of you enters the
mosque, let him send salams upon the Prophet (blessings and peace of Allah
be upon him), then let him say, Allahumma aftah li abwab rahmatika (O
Allah, open to me the gates of Your mercy). And when he leaves let him send
salams upon the Prophet (blessings and peace of Allah be upon him) and say
Allahumma i‘simni min
ash-shaytan ir-rajeem
(O Allah, protect me from the accursed Shaytan).” Classed as saheeh by
al-Albani in Saheeh Ibn Maajah. 

·       
Seeking the protection of Allah against the Shaytan and not being afraid of
him, whilst taking all precautions against his evil by obeying and
remembering Allah 

Allah, may He be exalted, says
(interpretation of the meaning):

Indeed,
the plot of Satan has ever been weak.
[an-Nisa’
4:76]

{Indeed,
there is for him no authority over those who have believed and rely upon
their Lord.

His authority
is only over those who take him as an ally and those who through him
associate others with Allah.} [an-Nahl 16:99, 100]. 

Abu Sulayman ad-Darani (may
Allah have mercy on him) said: 

Allah has not created any
creation more insignificant to me than Iblees. Were it not that I have been
instructed to seek refuge from him, I would never have sought refuge from
him at all. If he were to appear before me, I would simply strike him on the
face. End quote from Tareekh Dimashq (34/140) 

·       
Always reciting the adhkar of morning and evening, and the adkhar for going
to sleep and waking up, and the adhkar of prayer, and other specific adhkar,
and performing ruqyah as prescribed in Islam. These are among the greatest
means by which the Muslim can protect himself against the tricks, whispers
and insinuating thoughts of the Shaytan 

·       
Resisting waswas and passing thoughts, and not giving free rein to them 

Ibn al-Qayyim (may Allah have
mercy on him) said: 

Ward off the passing thought,
for if you do not do that, it will become an idea. Ward off the idea, for if
you do not do that it will become a desire. Then fight it, for if you do not
do that it will become a resolve and ambition, and if you do not ward it off
it will become an action. If you do not counter it with its opposite, it
will become a habit, and then it will be difficult for you to get rid of it.
End quote from al-Fawaid (p. 31) 

What the Muslim must do is
resist these whispers and passing thoughts lest they take control and the
problem become serious. 

·       
Keeping company with good people who will encourage you to do good, so that
the Shaytan will find no way to reach the heart of the son of Adam, and
keeping away from the company of evil people whom the Shaytan uses as a
means to reach the heart of the son of Adam. 

If a person keeps company with
good people, his mind will be focused on their company and on what they are
teaching him and advising him to do. But if he keeps company with evil
people, his mind will be focused on the falsehood that he hears from them
and that they encourage him to engage in. 

·       
Remembering Allah a great deal, reciting Quran, praying, and focusing on
righteous deeds, both outwardly and inwardly 

Al-Bukhari (6407) narrated that
Abu Moosa al-Ash‘ari (may Allah be pleased with him) said: The Prophet
(blessings and peace of Allah be upon him) said: “The likeness of the one
who remembers his Lord and the one who does not remember his Lord is that of
the living and the dead.” 

Ibn al-Mubarak narrated in
az-Zuhd (2/17) that Salman (may Allah be pleased with him) said: Every
man has an inward aspect and an outward aspect. Whoever takes care of his
inward aspect, Allah will take care of his outward aspect, but whoever
causes his inward aspect to become corrupt, Allah will cause his outward
aspect to become corrupt. 

·       
Remembering Allah when entering the house and when leaving it 

Muslim (2018) narrated from
Jabir ibn ‘Abdullah that he heard the Prophet (blessings and peace of Allah
be upon him) say: “When a man enters his house, and mentions Allah when he
enters and when he eats, the shaytan says: ‘You have no place to stay and no
dinner.’ But if he enters and does not mention Allah when he enters, the
shaytan says, ‘You have found a place to stay.’ And if he does not mention
Allah when he eats, he says: ‘You have found a place to stay and dinner.’” 

Abu Dawood (5095) narrated from
Anas ibn Malik that the Prophet (blessings and peace of Allah be upon him)
said: “When a man goes
out of his house and says: ‘Bismillah, tawakkaltu ‘ala Allah wa la hawla
wa la quwwata illa Billah (In the name of Allah, I put my trust in
Allah, there is no power and no strength except with Allah),’ then it is
said: ‘You have been guided, sufficed and protected,’ and the devils go far
away from him, and another devil says: ‘what can you do with a man who has
been guided, sufficed and protected?’”
Classed as saheeh by al-Albani
in Saheeh Abi Dawood. 

Whoever Allah protects against
the Shaytan when he comes in and goes out, He will protect him from his
waswas and whatever he makes fair-seeming to him of evil. 

·       
Refraining from whims and desires, whilst adhering to the limits set by
Allah 

Sahl ibn ‘Abdullah (may Allah
have mercy on him) said: “The individual must restrain his faculties and
adhere to the limits set by Allah, and he must rein in his whims and
desires. If he does that, Allah, may He be exalted, will protect his heart
(from evil thoughts) and make his mind think aright. End quote from Bahr
al-Fawaid by al-Kalabadhi (p. 125) 

·       
Seeking knowledge and focusing on that, for knowledge is light that revives
the heart and dispels ignorance, and it dispels waswas and whatever bad
thoughts one may be entertaining 

The one who focuses his thinking
on issues of knowledge, and contemplates in his mind the different views of
the scholars, and their various opinions and methodologies in dealing with
those issues, will bar the way to the Shaytan and he will keep away from his
heart and mind. 

Thirdly: 

The ways in which a person may
make his actions sincerely and purely for Allah in all his affairs are many
and varied. They include the following: 

·       
He should make his words match his deeds and his outward actions match his
inward thoughts. 

·       
He should make his deeds in accordance with that which is prescribed, that
which Allah loves and is pleased with, and grants reward for. 

·       
By doing this righteous deed, he should seek the Countenance of Allah and
the Hereafter. 

·       
He should keep away from bid‘ah (innovation) and every path that leads to
it, and he should avoid keeping company with those who follow innovation and
whims and desires, whilst also adhering to the Sunnah and keeping company
with those who follow it, for a person will follow the way of his close
friend. 

·       
He should take care to be sincere, from the heart, and he should strive to
purify himself and cleanse his heart of shirk, showing off and seeking a
reputation. 

·       
He should follow the path of asceticism and lack of interest in worldly
gain; he should turn away from that, focusing  instead on obedience to Allah
and turning to Him, without going to extremes. 

·       
He should be sincere towards Allah in his resolve to do good and when doing
it. Allah, may He be exalted, says (interpretation of the meaning): 

Obedience
and good words. And when the matter [of fighting] was determined, if they
had been true to Allah, it would have been better for them.(Muhammad
47:21).

He should not be one of those
who engage only in  mere wishful thinking, which is of no benefit if it is
not followed by righteous deeds and seeking reward with Allah. 

·       
His food, drink and clothing should all be from good, halal sources. 

·       
He should love for his Muslim brothers what he loves for himself of good,
and he should hate for them what he hates for himself of evil. 

·       
He should fulfil the words of Allah, may He be exalted (interpretation of
the meaning):

{Say,
“Indeed, my prayer, my rites of sacrifice, my living and my dying are for
Allah, Lord of the worlds.

No partner has He. And this I have been commanded, and I am
the first [among you] of the Muslims.”} (al-An‘am 6:162-163).  

All his actions should be
preceded by sound intentions as much as possible, including when he eats,
drinks, does his work, is intimate with his wife, keeps company with his
friends and mixes with people 

·He should study
the biographies of righteous people among the slaves of Allah, those who are
known for their sincerity towards Allah and their sincerity in their
actions, and he should do as they did and strive to imitate them, for
whoever imitates a people is one of them, and whoever loves a people will be
gathered with them (on the Day of Resurrection). 

For more information, please see
the answer to questions no.

126306 and

162186

And Allah knows best.