26:89Ash-Shu'araa

“No worshipper has ever said: None has the right to be worshipped but Allah (Lā ilāha illallāh)’ sincerely, except that the gates of heaven are opened for it, until it reaches to the Throne, so long as he avoids the major sins.”

“Whoever meets Allah with no mark on him (as a result of fighting) in His cause, he will meet Him with a deficiency.”

The Prophet (ﷺ) said, "Whoever said "None has the right to be worshipped but Allah and has in his heart good (faith) equal to the weight of a barley grain will be taken out of Hell. And whoever said: "None has the right to be worshipped but Allah and has in his heart good (faith) equal to the weight of a wheat grain will be taken out of Hell. And whoever said, "None has the right to be worshipped but Allah and has in his heart good (faith) equal to the weight of an atom will be taken out of Hell."

“It was said to the Messenger of Allah (ﷺ): ‘Which of the people is best?’ He said: ‘Everyone who is pure of heart and sincere in speech.’ They said: ‘Sincere in speech, we know what this is, but what is pure of heart?’ He said: ‘It is (the heart) that is pious and pure, with no sin, injustice, rancor or envy in it.’”

This hadith has been narrated, on the authority, of Abu Huraira (with this change of words)." A person whose heart is attached to the mosque when he goes out of it till he returns to it."