Thank you for the interpretative question, “If borders are biblical, is it because of Acts 17:26?”
If I may suggest that borders are biblical
The text says this, “24 The God who made the world and everything in it is the Lord of heaven and earth and does not live in temples built by human hands. 25 And he is not served by human hands, as if he needed anything. Rather, he himself gives everyone life and breath and everything else. 26 From one man he made all the nations, that they should inhabit the whole earth; and he marked out their appointed times in history and the boundaries of their lands. 27 God did this so that they would seek him and perhaps reach out for him and find him, though he is not far from any one of us” (NIV).
Here are some thoughts on borders:
A. The reason God established borders was so that man can filled the earth. It is God’s plan that man rule over the earth (Gen. 1:28).
Genesis 1 says this, “God blessed them and said to them, “Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground” (NIV).
B. The reason God established borders was so people would seek and find him.
As people spread throughout the earth, it is God’s plan that humans will seek and find him. It is part of God’s plan that his people become witnesses before the various people groups.
Acts 1:8 says this, “But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth” (NIV).
The discovery of the Creator God comes through his people who travel through the world or that its traders will come in contact with God’s people. Wherever the people group is in this world, it is God’s will that they come to hear and believe in him.
Those individuals who come to faith in God may return to their home country or tell fellow countryman of the God whom they have come to believe.
Summary: Borders are not an end in itself. It is a means to the end. God set boundaries even borders so that in their circumstances people will seek for God. God will bring people to them so that they will believe in him.
-Kingston