No danger to Christians in Qatar, i've been here almost 5 years, congregating on a protestant non-denominational church, and have never had an issue... if you are Catholic or Anglican there are temples in the way to the industrial area, i understand there are mass on friday saturday and even sunday... if are protestant, there are one church near the rugby club in Doha, one in west bay area and another one in al khor (not sure if al khor or dukhan), in the protestant ones, services are only on fridays, during the week there are praying services, and family meetings.. and again, no need to worry about your religious life if dont mess it...
blessings