What is the ruling on looking at a cross, using programs with cross-shaped icons, and following a doctor or teacher who wears a cross around his neck?

It is permissible to merely look at a cross and to use programs that contain a cross icon, and to follow a doctor who wears a cross. The cross icon should be removed from the device if possible. It is forbidden for the doctor to wear a cross, and he must remove it. He should be advised regarding this. The Prophet, peace and blessings be upon him, would not leave anything in his house that contained crosses except that he would break it. He commanded anyone who saw a garment with a cross on it to remove it, and he commanded Adi ibn Hatim to remove the cross from his neck. The disbelieving doctor should be invited to Islam. It is permissible to deal with a disobedient Muslim doctor or a disbelieving doctor, but it is preferable to deal with a Muslim doctor. Removing the cross is the duty of the capable Muslim ruler, and ordinary individuals should not undertake it for fear of tribulation. It is not permissible to change an evil if it leads to a greater evil.