Below is the civil marriage index record for James and Elizabeth in 1876. The actual record will show the names of the fathers of the bride and groom and where the bride and groom were living in 1876. Once you have the father's names it may be easier to locate a baptismal record for James and Elizabeth.
If you go to the GRONI site, you should be able to get a copy of the marriage record for around 2 pounds.
First name(s) James
Last name Gamble
Registration year 1876
Registered Quarter/Year 1876
Registration district Belfast
MarriageFinder? James Gamble married one of these people
Annie Gamble, Elizabeth Baird