But unto every one of us is given grace according to the measure of the gift of Christ.
But - though "one" in our common connection with "one Lord," etc., yet 'each' has assigned to him his particular gift (1 Corinthians 12:11) for the good of the whole: none is overlooked; none can be dispensed with for the edifying of the Church (Ephesians 4:12). A motive to unity (Ephesians 4:3). Translate, 'unto each one of us was the grace bestowed at Christ's ascension (Ephesians 4:8) given according to,' etc.
The measure - the amount "of the gift" which Christ gives (Romans 12:3; Romans 12:6).