I know the Orthodox tend to avoid subjects such as justification, and tend to focus on sanctification (theosis), which IMO is a great thing. But do most Orthodoxy completely ignore justification? It's all over scripture that our sins are forgiven and justified by faith.
I apologize for the length.
First and foremost, we are justified by Christ on the cross, crucified and risen. That justification is applied to us by participating in Christ's death and resurrection and living in communion with Him. And yes, we believe faith is necessary, but faith alone doesn't accomplish anything unless we act on it out of love.
We are joined to Christ through His death and resurrection and brought into His Body though baptism and chrismation.
Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection: Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin. For he that is dead is freed from sin. Now if we be dead with Christ, we believe that we shall also live with him: Knowing that Christ being raised from the dead dieth no more; death hath no more dominion over him. For in that he died, he died unto sin once: but in that he liveth, he liveth unto God. Likewise reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord. Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof. Neither yield ye your members as instruments of unrighteousness unto sin: but yield yourselves unto God, as those that are alive from the dead, and your members as instruments of righteousness unto God.
It's not just enough to be dead to sin, but we must also be alive to God. This means maintianing communion with Him through His Son Jesus Christ.
We do this by living as members of His Body, trhe Church. This communion is maintained and expressed through our celebration of the Eucharist.
1 Cor 12:12-14
For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ. For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.For the body is not one member, but many.
1 Cor 10:16-17
The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ? For we being many are one bread, and one body: for we are all partakers of that one bread.
And just as we have a tendency to return to sin, we can return to the Lord through repentence and confession. Having fallen back down, we must hate our sin, turn from it, and return to God in faith that we will be received back. We do this both privately in prayer and sacramentally in confession be cause we are called to members of the Body.