Finally, who's got the whole world in his hands? Christ, ultimately (2,4)
I believe the answer is:
at last
'finally' is the definition.
(synonyms)
'who's got the whole world in his hands? christ ultimately' is the wordplay.
'who's got the whole world in his hands?' becomes 'atlas' (reference to the Greek titan who held the Earth).
'ultimately' says to take the final letters.
The final letter of 'christ' is 't'.
'atlas'+'t'='AT LAST'
(Other definitions for at last that I've seen before include "Where a snob worked" , "'In the end (2,4)'" , "working as a cobbler?" , "Where cobbler located" , "Finally, having waited a long time" .)