A principal rule in the Islamic jurisprudence states that Muslims are forbidden to buy, sell, gift, or support anything that is forbidden in the Islamic Shari`ah. This principle is based on the Qur’anic verse, in which Allah Almighty says: “And help one another in goodness and piety, and do not help one another in sin and aggression; and be careful of (your duty to) Allah; surely Allah is severe in requiting (evil).” (Al Ma’idah 5:2)

Moreover, Muslim jurists say that selling to non-Muslims symbols of their religions is undoubtedly forbidden. Sheikh al-Islam Ibn Taymiyah says in his well-known book Iqtida’ al-Siraat al-Mustaqeem: If the things they (non-Muslims) buy are used to do haram (forbidden) things, such as crosses, baptismal fonts, meat that has been slaughtered for anyone or anything other than Allah, images and so on, then they are undoubtedly haram...

Therefore, giving items such as crosses to a friend as a gift is haram.

Furthermore, every Muslim should be a Caller to Allah by practicing the Islamic Shari`ah in his daily life, and spreading the message of Islam to everyone he deals with.