Common, Appropriate Words To Congratulate Muslims At The Beginning Of Ramadan

1.    "Ramadan Kareem!"
("Noble Ramadan!")

2.    "Ramadan Mubarak!"
("Blessed Ramadan!")

3.    "Kul 'am wa enta bi-khair!"

("May every year find you in good health!")

Making Supplications On Birthday

Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright. We bear witness that there is none worthy of worship but Allah Alone, and we bear witness that Muhammad (saws) is His slave-servant and the seal of His Messengers. 

Every people have a culture and Islam too has its own culture; and celebrating one’s birthday with a feast cannot be considered a part of Islamic culture.  If one trusts, obeys, and follows the guidance and commands of Allah and His Messenger (saws),   one can be assured of never ever being misled; but if one believes, obeys and follows any other guidance, other than that of Allah and His Messenger (saws), one can be assured of being led astray.