from Orthodoxwiki.com -
Marriage service
Wedding at Cana
"For the Orthodox Christian, the marriage service (wedding) is the Church's formal recognition of the couple's unity, a created image of God's love which is eternal, unique, indivisible and unending. The early Church simply witnessed the couple's expression of mutual love in the Church, and their union was blessed by their mutual partaking of the Holy
Eucharist.
When a marriage service developed in the Church, it was patterned after the service for
baptism and
chrismation. The couple is addressed in a way similar to that of the individual in baptism. They confess their faith and their love of God. They are led into the Church in procession. They are prayed over and blessed. They listen to God's Word.
The service contains no vows or oaths. It is, in essence, the "baptizing and confirming" of human love in God by Christ in the Holy Spirit. It is the
deification of human love in the divine perfection and unity of the eternal Kingdom of God as revealed and given to man in the Church. There is no "legalism" in the Orthodox sacrament of marriage. It is not a juridical contract, it is a spiritual bond."
My wife and I were instructed by our priest that marriage is a vocation just like the priesthood or monasticism. He also taught us that the job of a person in a marriage is to look after with great attentiveness the salvation and well being of their spouse. If you think about it, this removes any question of "validity" and asks only "are you doing your job?" and if you are falling short (which is almost always true to some degree) it is the job of your priest and your church family to help you get that on track.