The Reward For Having a Sincere Intention.
Allaah The Most High said,
“So worship Allah (Alone) by doing religious deeds sincerely for Allah’s sake only…” (Soorah az-Zumar 39:2)
Umar (RadhiAllaahu Anhu) reported from Allah’s Messenger (Sallalahu Alayhee Wasallam) said, “The reward of deeds depends upon the intention and every person will get the reward according to what he has intended. So whoever emigrated for Allah and His Apostle, then his emigration was for Allah and His Apostle. And whoever emigrated for worldly benefits or for a woman to marry, his emigration was for what he emigrated for.” (Saheeh al-Bukhaari, Kitaab al-Eemaan no.54)
Sa’ad bin Abee Waqqaas (RadhiAllaahu Anhu) reported from Allaahs Messenger (Sallalahu Alayhee Wasallam) said, “You will be rewarded for whatever you spend for Allah’s sake even if it were a morsel which you put in your wife’s mouth.” (Saheeh al-Bukhaari, Kitaab al-Eemaan no.56)
A Sincere Intention Saves You From The Hell Fire
Amr bin Deenaar said I heard Jaabir bin Abdullaah say I am from those who was with Mu’adh (bin Jabal RadhiAllaahu Anhu) at the time of his demise he said, “Move the cover of the tent, as I will narrate a hadeeth to you I heard from the Messenger of Allaah (Sallalahu Alayhee Wasallam).” he repeated it and said, “I will inform of you of something I heard from the Messenger of Allaah (Sallalahu Alayhee Wasallam) and what stopped me from telling you was that I feared you might rely on it. I heard him (ie the Messenger of Allaah (Sallalahu Alayhee Wasallam) say, “Whoever testifies sincerely and with certainty from his heart that that there is no true deity except Allaah, will not enter the Fire and will go to Paradise,” he said again, “He will enter Paradise and the Fire will not touch him” (Musnad Ahmad 5/236, Musnad Humaidee no.369, Ibn Hibbaan authenticated it, Saheeh Ibn Hibbaan no.200)
Statement Of The Salaf Concerning Having A sincere Intention.
1) Imaam Sa’eed ibn al-Musayyab said when Abu Bakr (RadhiAllaahu Anhua) climbed the Minbar on the day of Jumu’ah Bilaal (RadhiAllaahu Anhua) said to him, “Did you free me (from slavery) so that I become your servant or did you do it for the sake of seeking Allaahs pleasure? To which Abu Bakr replied, “To seek Allaahs pleasure.” So Bilaal (RadhiAllaahu Anhu) said, “Then give me permission to go on war expeditions.” So he was granted permission, he travelled to Shaam and that was where he passed away. (Siyaar al-A’laam an-Nabula 1/357)
2) Imaam Abu Haazim said, “Hide your good deeds just as you hide your bad deeds.” (Siyaar al-A’laam an-Nabula 6/100)
3) Imaam Rabee’a bin Khaitham, “Any action that is done for the sake of ostentation and not for the sake of Allaah is wasted.” (Siyaar al-A’laam an-Nabula 4/259)
4) Imaam Sufyaan ath-Thawree said, “There is not a better or more virtuous action then knowledge which has been sought with a sincere intention.” (Siyaar al-A’laam an-Nabula 7/244).
5) Imaam Mu’ammar said, “When someone wishes to seek knowledge for the sake of other than Allaah, the knowledge rejects it, knowledge is only sought when it is done for the sake of seeking Allaahs pleasure.” (Siyaar al-A’laam an-Nabula 7/17)
6) Imaam Abdullaah ibn Mubaarak said, “How many actions are there that are small but a sincere intention makes them bigger and how many actions are big but insincerity makes them small.” (Siyaar al-A’laam an-Nabula 8/400) (Saheeh Fadhail A’maal of Abdul Khaaliq Siddeeque pg.33-35
Ahlul hadeeth - The Way Of The Salaf 