Is it necessary to curse friends in response to their cursing to avoid appearing weak?

It is permissible to retaliate against an offense in kind with insults and invectives, without transgressing prohibitions such as lying or declaring someone an infidel. However, forgiveness and forbearance are better, as these are noble Islamic virtues that demonstrate clemency and increase one's reward with Allah, unless the situation necessitates a response due to an overriding necessity.