And again, Isaiah says,
“The Root of Jesse will spring up,
one who will arise to rule over the nations;
in him the Gentiles will hope.”
May the God of hope fill you with all joy and peace as you trust in him, so that you may overflow with hope by the power of the Holy Spirit.
The context of this passage (14:1-15:13) is aptly entitled in the NIV heading, “The Weak and the Strong.” What was happening in the change that Jesus brought was the fulfillment of what was promised, something radically new, and not anticipated by anyone. God was opening the door for full participation in the people of God for all, simply by faith in Jesus as Messiah, Lord and King. Faith was the marker, not circumcision or the practice of the Torah, the Law. Which now would be fulfilled through the Spirit on the basis of Christ’s atoning work (Romans 8:1-17).
In one sense I think Paul is especially addressing the Jews at this point, because the radical change which had come had put their practice of the faith up in the air, the primary marker of their identfication as God’s people, circumcision, now replaced with baptism (Colosssians 2:11-12). So that those who still felt they had to abide by something of the Law of Moses are said by Paul to be potentially “weak” in their faith (but not necessarily so). And those who are “strong” in their faith can (if they so choose) let go of what had previously marked God’s people in their adherence in practice to the Torah, the Law given to Moses on Mount Sinai. What was insisted on was the new freedom from the old boundaries through the work of the Spirit, bringing in a new order which in and under Christ constituted the kingdom of God, even the church, consisting of all Jews and Gentiles who put their faith in Jesus as the Messiah.
As such, the Advent hope realized in the coming of “The Root of Jesse” (Jesse, the father of King David) would result in complete joy and peace through trust in him, that is in Jesus. So that they would overflow with hope through the power of the Holy Spirit at work in their lives. This would be especially realized in their association with each other, their salvation in Jesus evident, in spite of what differences they would have. Their hope to which the Law and everything pointed to, was fulfilled in Jesus, so that this hope makes a difference now in the present, as well as the future, as we look forward to the completion of what has begun and is going on now in and through King Jesus.