63. On the supposition, that there never was to be but one individual in the world, at any one time, who was properly a complete Christian, in all respects of a right stamp, having Christianity always shining in its true luster, and appearing excellent and lovely, from whatever part and under whatever character viewed: Resolved, to act just as I would do, if I strove with all my might to be that one, who should live in my time. Jan.14′ and July ’3′ 1723.
Jonathan Edwards is saying here that there can only be one person who at any one time is 'the strongest Christian alive'. And the goal for his life is to be that man. Let us seek to have this attitude.