As a new-Muslim, one needs to learn the ethics, morals, and beliefs of Islam, but in a proper way. A gradual approach could be successful, especially in difficult-to-change issues. For example, one may start by teaching a new revert the Islamic stance on Jesus. You may study some relevant Qur’anic surahs or verses. In doing so, you could resort to helpful means such as books, CDs, etc. Also, imam of the masjid could help in this regard. One of the fruits of this is that the new convert will realize why Muslims don’t wear crosses.
The eminent Muslim scholar and renowned da`iyahSheikh `Abdel Khaliq Hasan Ash-Shareef says: A new revert may keep the necklace on the condition of detaching the cross and getting rid of it. Wearing the necklace with the cross contradicts with their Muslim beliefs. A revert should not wear the cross even if it is for the sake of family or anyone.
Here, we recall that the Prophet (peace and blessings be upon him) once said to `Adiy ibn Hatim (may Allah be pleased with him) when he came to him wearing a golden cross on his neck: “take off this idol.” (al-Tirmidhi)