There is no harm in celebrating Mawlid if performed within laws of shariah. Praising Nabi (sallallahu Alayhi waSallam) through Sermons, Naats will increase Eemaan & love towards Nabi (A.S.).

Ya Nabi Salaam Alaikum Ya rasool Salam Alaikum, Ya Habeeb Salam Alaikum, Swalawatullah Alaikum.