The northern cardinal does indeed mate for life.

Thank you. would about offsprings? do other birds attack them or their nest? i have a couple that has been in a bush for at least two years and the other cardinals appear to be their offsprings, but how would i know?

It is hard to tell if they would be the offspring of your original pair:

“Annual survival rates for adult Northern Cardinals have been estimated at 60 to 65%,[19] however, as with other passerine birds, the high mortality of juveniles means that the average lifespan is only about a year.”

Source

Trevor Miller of the St Louis has been married 14 times, so mating for life in his case is a serial event

Thanks Marina. i guess i need to put a collar on my pair of cardinals so i can identify them. just kidding. wow, its cold here 9 above and wind will freeze your tonsils, so i keep my mouth shut. john

I wish I had cardinals living near my house.