according to shia its allowed a shia marry a sunni. about sunni it depends on the sect.
there are many difference between a suni and a shia suni say that there are four khalifha but shias say that there is only one khalifha hazrat ALI
Caliphs. Shia and sunni have mainly conflict on Imamat (leadership). shia say Imamat is one of 5 pillars of Islam and only God can select leader for people. Sunnis say Imamat is not part of Islam and leader can be selected by people by any method like shura (a kind of democracy)
Iran is the main Shia country and leader of other shia countries. Shia doctrine has root in Karbala. When tragedy of Karbala happened most of Iranians understood there is two kind of Islam and at that time most of Iranians became Shia and from that time Iranians are following "The Fourteen Infallibles" and even follow their lives for them like what they did in Iranian Revolution Iran-Iraq War. now Shia Muslims have at least 120,000 Hadith (sayins) from The Fourteen Infallibles that is the base of Shia Islam. Shia believes sayings of The Fourteen Infallibles are from God because they are Representative of God in earth and they do not say anything from themselves.
You should clarify what religion you are talking about. There are several religions in Persia (Iran); including Shia Islam, Sunna Islam, Bahá'í Faith, Christianity, Judaism, and Zoroastrianism.
You say ' Merry Christmas' in the UK.
Just as in your question !They tend to say "Happy Christmas" instead of "Merry".Merry Christmas
Hanukkah is a holiday, not a language. You cannot say "Merry Christmas in Hanukkah. That's like asking: "How do you say Merry Christmas in Easter" I think he means how do you say merry Christmas in Hebrew
merry christmas
merry chrismack
merry christmas
merry chrismat
Merry christmas