assalamualikum i want to know if this is a sin. i asked one of my colleagues that if they could cover my hours and they said no because they have to attend church and then I said to them ok if you dont go (church) youll be sinning, i dont beleive this in my heart. i then i asked her if their freind can cover my hours and she said maybe, then i asked " dont they go church" and she said "no" the i joked to her okay i will tell her off about it. is any of this blasphemous please let me know

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

Undoubtedly, the two statements that you uttered were seriously grave because they implied the approval of those people's going to church and that it is a religious obligation which they are held sinful if they fail to observe it.

It is well-known that the Christians go to church in order to perform polytheistic rituals that involve glorifying the cross and so on. Verily, such matters should not be a subject of jokes. Allaah, The Exalted, says (what means): {And if you ask them, they will surely say, “We were only conversing and playing.” Say, “Is it Allaah and His verses and His Messenger that you were mocking?”} [Quran 9:65]

Ibn Al-‘Arabi commented on this verse saying, “Their statements are either said seriously or in jest; in both cases it is considered an act of disbelief (whether they were spoken seriously or in jest). Apostasy occurs when one commits any of the actions that nullify Islam, even if done in jest, according to the consensus of all Muslims. Seriousness is the brother of truth and knowledge, and jest is the brother of falsehood and ignorance.” [Ahkaam Al-Quraan]

Negligence with regards to uttering such statements and taking them lightly may lead the person to his own destruction. The Prophet, sallallaahu ‘alayhi wa sallam, said: “A slave (of Allaah) may utter a word which pleases Allaah without giving it much importance, and because of that Allaah will raise his rank. Likewise, a slave (of Allaah) may utter a word (carelessly) which displeases Allaah without thinking of its gravity and because of that he will be thrown into Hellfire.” [Al-Bukhari]

Al-Haafith Ibn Hajar commented on the Hadeeth saying, “This Hadeeth means that this person does not think about the words before uttering them, ponder on their consequences, or believe that they are of any significance.” This is similar to the verse that reads (what means): {… and thought it was insignificant while it was, in the sight of Allaah, tremendous.} [Quran 24:15]

Hence, it is incumbent on you to turn to Allaah in repentance for what you had said and you should not do that again in the future.

Please refer to Fatwa 86527 about the conditions for repentance.

Allaah Knows best.