A couple of quotes:
1) Thus, we do not strictly distinguish between justification and sanctification, but understand them as two sides of the same process, or as St. Paul says in 1 Corinthians 6:11, “You were washed, you were sanctified, you were justified into the Name of our Lord Jesus Christ and by the Spirit of our God.”
2) we are declared righteous because we share in the life of Christ. He was justified by His resurrection from the dead, and we are justified through our participation in His death and resurrection by the Holy Spirit.
However, as varied as the Orthodox writers can be on subjects in published journals, I do not take this as an official stance.