Did the timing of Christ's coming matter in history?
Yes. Christ came at the exact right moment in time according to the predetermined counsel of God. History would not have worked out right had He come a hundred years sooner or a hundred years later. His coming and crucifixion were part of God's foreknown plan set before creation.
Les teaches that a Redeemer was promised immediately after the human race fell out of fellowship with its Creator, and that this Redeemer was prophesied all the way through the Old Testament according to God's predetermined counsel. Then, one day, He came at the exact right moment. Les emphasizes that history would never have worked out right if Christ had come a hundred years sooner or a hundred years later. He came according to the predetermined counsel of the Godhead. Les also points out that God's foreknowledge meant He knew the crucifixion and slaying beforehand; it was all in the predetermined plan of the ages, before anything was created. Everything unfolding over 6,000 years of human history has been right on schedule, and the Lord's coming will not be an hour late or early.