Praise be to Allah.
The practice of the Prophet (blessings and peace of Allah be upon him) was to remove the image of the cross if he found it on a garment, mat or anything else. He did not approve of leaving the symbol of a distorted religion that falsely affirmed that the Messiah ‘Eesa ibn Maryam (Jesus son of Mary, peace be upon him) had been crucified, to the extent that this symbol became sanctified, venerated and worshipped by the followers of that religion.
It was narrated from ‘Aa’ishah (may Allah be pleased with her) that the Prophet (blessings and peace of Allah be upon him) would not leave anything in his house on which there were crosses except he would erase them. Narrated by al-Bukhaari (5608).
The scholars of the Standing Committee for Issuing Fatwas were asked:
What is the ruling on wearing clothes on which there are crosses, and we did not know that they were there when we bought it, because it is not in the usual form, such that we could have recognised it before buying it; rather it is in an unusual and unclear form. What is the ruling on wearing it?
If you find out that there are crosses on clothes after buying them, then it is forbidden to pray wearing them, and you must remove the cross by whatever means will remove its image, by scratching it off or dyeing it and the like. That is because of the report narrated by al-Bukhaari in his Saheeh from ‘Imraan ibn Hattaan, that ‘Aa’ishah (may Allah be pleased with her) said: the Prophet (blessings and peace of Allah be upon him) would not leave anything in his house on which there were crosses except he would erase them.
Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-‘Azeez Aal ash-Shaykh, Shaykh ‘Abdullah ibn Ghadyaan, Shaykh Saalih al-Fawzaan, Shaykh Bakr Abu Zayd
Fataawa al-Lajnah ad-Daa’imah (24/19)
How can the Muslim accept to put on his garment the image of an idol that is worshipped instead of Allah, and is symbolic of a distorted religion and false belief, that was declared false by the Holy Qur’an: “And they did not kill him, nor did they crucify him; but [another] was made to resemble him to them” [an-Nisa’ 4:157]?
The shar‘i ruling on wearing it is clear; it is forbidden. Allah has promised those who fear Him relief from their calamity and provision from where they do not expect it. He, may He be exalted, says (interpretation of the meaning):
“And whoever fears Allah - He will make for him a way out
And will provide for him from where he does not expect. And whoever relies upon Allah - then He is sufficient for him. Indeed, Allah will accomplish His purpose. Allah has already set for everything a [decreed] extent”
And Allah knows best.