The sacred/secular divide that we hear about so often is a thing that exists only as a result of sin. In a world without sin, whether we think of Eden or of the world to come, everything is filled with the glory of God, and there is no "secular." The earth is holy. Again, when Christ was in the world bodily, the kingdom of heaven was breaking in and the divide between the sacred and secular was breaking down. Sin and disease and hard-heartedness struggled for existence in the face of God's presence.
One call we Christians have in this world is to carry God's presence with us wherever we go, not as a hidden presence but as a redeeming presence. We know what God's presence does because we saw it in Christ: welcoming sinners and seeking out the outcasts, binding up the brokenhearted, comforting the afflicted but troubling the self-righteous and the complacent. God's presence welcomes the stranger, it creates brothers and sisters for us all, and it shows us a face by which we will know we are home. By love it creates a place where people gather for the hope that someone there will hear them, someone there will know them, someone there will call them by name and treasure them.
The sacred/secular divide breaks down whenever we dare to really know another person.