Is buying and wearing an engagement ring forbidden merely because it resembles non-believers, or has it become a widespread custom among people, unaccompanied by any belief, and what is closer to Allah's pleasure?

Wearing an engagement ring (dublah) is not from the Sunnah (definition) of the Prophet, peace and blessings be upon him, nor was it known to be practiced by Muslims. It is preferable not to wear it due to the suspicion of imitating the customs of disbelievers. It is not forbidden if there is no intention of imitation or belief in its effect on bringing affection, but abstaining from it is more preferable. It is forbidden for the fiancé to put the ring on his fiancée because it is not permissible for him to touch her before the legitimate marriage contract.