What does it mean to return back to the Church?

Commenting on the parable of the lost coin (Luke 15:8–10), St. Ambrose says, “Moreover the woman did not idly rejoice to find her coin. This is no ordinary coin, on which is the image of the Emperor. And, therefore, the image of the King is the register of the Church. We are sheep: let us pray that He deign to place us beside the water of rest (Ps. 22:2). We are sheep, I say: let us seek pastures; we are coins: let us have a price. We are sons: let us hasten to the Father”¹¹⁰⁴

1103 St. Ambrose of Milan, Exposition of the Holy Gospel According to Saint Luke , trans. Theodosia Tomkinson (Etna, CA: Center for Traditionalist Orthodox Studies, 1998): p. 318.

1104 St. Ambrose of Milan, Exposition of the Holy Gospel According to Saint Luke , trans. Theodosia Tomkinson (Etna, CA: Center for Traditionalist Orthodox Studies, 1998): p. 317.