{The love of Christ} (h(8820)agap(8820)tou Christou). Subjective
genitive, Christ's love for Paul as shown by verse  15 .
{Constraineth us} (sunechei h(886d)as). Old and common verb, to
hold together, to press the ears together ( Ac 7:57 ), to press
on every side ( Lu 8:45 ), to hold fast ( Lu 22:63 ), to hold
oneself to ( Ac 18:5 ), to be pressed (passive,  Lu 12:50  Php
1:23 ). So here Paul's conception of Christ's love for him holds
him together to his task whatever men think or say. {Judging
this} (krinantas touto). Having reached this conclusion, ever
since his conversion ( Ga 1:17f. ). {One died for all} (heis
huper pant(936e) apethanen). This is the central tenet in Paul's
theology and Christology. Huper (over) here is used in the
sense of substitution as in  Joh 11:50  Ga 3:13 , death in behalf
so that the rest will not have to die. This use of huper is
common in the papyri (Robertson, _Grammar_, p. 631). In fact,
huper in this sense is more usual in Greek than anti, pro or
any other preposition. {Therefore all died} (ara hoi pantes
apethanon). Logical conclusion (ara, corresponding), the one
died for the all and so the all died when he did, all the
spiritual death possible for those for whom Christ died. This is
Paul's gospel, clear-cut, our hope today.