I like reading dead guys. Their thoughts have endured the test of time for a reason, and they rarely change their opinions. Here are a few comments from J. C. Ryle on John 8:56:
“[B]y faith [Abraham] looked forward to the day of our Lord’s incarnation yet to come, and as he looked he ‘was glad.’ That he saw many things, through a glass darkly, we need not doubt. That he could have explained fully the whole manner and circumstances of our Lord’s sacrifice on Calvary, we are not obliged to suppose. But we need not shrink from believing that he saw in the far distance a Redeemer, whose advent would finally make all the earth rejoice. And as he saw it, he ‘was glad.’
“The plain truth is, that we are too apt to forget that there never was but one way of salvation, one Savior, and one hope for sinners, and that Abraham and all the Old Testaments saints looked to the same Christ that we look to ourselves. We shall do well to call to mind the Seventh Article of the Church of England—‘The Old Testament is not contrary to the New—for both in the Old and New Testament everlasting life is offered through Christ, who is the only Mediator between God and man, being both God and man. Wherefore they are not to be heard, who assume that the old Fathers did look only for transitory promises.’ This is truth that we must never forget in reading the Old Testament. This is sound speech that cannot be condemned.”