by the "strength" of Christ is meant, not his strength as the mighty God...

The Lord always hears and answers his people sooner or later, in one form or another, though not always in the way and manner they desire; but yet in such a way as is most for his glory and their good: the apostle had not his request granted, that Satan might immediately depart from him, only he is assured of a sufficiency of grace to support him under the exercise, so long as it should last.