Yet to us there is one God, the Father (all' hēmin heis theos ho patēr). B omits all' here, but the sense calls for it anyhow in this apodosis, a strong antithesis to the protasis (even if at least, kai eiper).
Of whom (ex hou). As the source (ex) of the universe (ta panta as in Rom 11:36; Col 1:16.) and also our goal is God (eis auton) as in Rom 11:36 where di' autou is added whereas here di' hou (through whom) and di' autou (through him) point to Jesus Christ as the intermediate agent in creation as in Col 1:15-20; Joh 1:3. Here Paul calls Jesus
Lord (Kurios) and not
God (theos), though he does apply that word to him in Rom 9:5; Tit 2:13; Col 2:9; Act 20:28.