Strengthen the weak hands,
and make firm the feeble knees.
Say to those who are of a fearful heart,
'Be strong, fear not!
Behold, your God will come with vengeance,
with the recompense of God.
He will come and save you'. (Is. 35.3-4)
Steadfast love and faithfulness will meet;
righteousness and peace will kiss each other.
Faithfulness will spring up from the ground,
and righteousness will look down from the sky. (Ps. 84.10-11)
'Which is easier, to say "Your sins are forgiven you" or "rise and walk"? But that you may know that the Son of Man has authority on earth to forgive sins'--he said to the man who had been paralyzed--'I say to you, rise, take up your bed and go home'. And immediately he rose before them, and took up that on which he lay, and went home, glorifying God. (Luke 5.23-25)
. . .
If I could add a fourth reading, a New Testament reading, to these, it would be from Hebrews 12:
For the moment all discipline seems painful rather than pleasant; later it yields the peaceful fruit of righteousness to those who have been trained by it. Therefore lift your drooping hands and strengthen your weak knees, and make straight paths for your feet, that what is lame may not be put out of joint but rather be healed. (vv. 11-13)
There is something in all of this about walking and righteousness, and peace and healing. The assumption is that our hands will be feeble and our knees weak, but that does not mean that we abandon the journey. Just the opposite: we continue the walking, making level (in the NASB translation) paths for our feet, so that the journey is one that heals rather than further disabling us.
I cannot help but connect the 'recompense' in Isaiah with the forgiveness and healing Jesus brings in Luke's gospel. God will come, and will set things right. And this is what it will look like: the blind see, the deaf hear, the lame walk. The forgiveness of God makes our way straight, makes the path for our feet level: we need not fear stumbling, not because we are strong (we're feeble!) but because it is God's mercy that cushions our fall, makes it possible for us to rise again, and walk.
In Jesus, faithfulness springs up from the earth: he is faithfulness, he is our peace, and in him God's steadfast love and righteousness come together, and come to us. This is what it looks like when the Lord comes to make things right, when all creation is restored, when our God comes to save us. In Jesus, the beloved responds in perfect fidelity to the lover, and we get caught up in that; when righteousness and peace kiss each other, we are drawn into the love that is divine and eternal, and we find ourselves hidden, safe, in the faithfulness and righteousness of the Lord.
In Advent this is what we expect God to do. All that we hear about God coming to save us finds expression in the life and ministry, the death and resurrection, of Jesus. He is the One who sets things right, the One who is our peace, in whom all things hold together. And as we yearn for the salvation of our God, we pray with the saints throughout the ages: Come, Lord Jesus!