From the Eastern Christian perspective, original sin marred the image of God within us. The only Person who could restore that image was the Image of God the Father Himself, namely the Son and Word of God Who became flesh in Jesus Christ. (This puts pay to the heretical notion that Christ was an angel before He became man - angels are not made in the image of God for one thing).
By uniting His Divinity with our humanity, by becoming Man in Jesus Christ, God the Son, the Divine Image of the Father, healed the alienation we experience through sin, restored us to God’s favour by having us participate in Him and deifies us through the Communion of His Body and Blood through the Holy Spirit.
He brings His saving Divinity into every aspect of human experience and by doing so, He saves and transfigures us.
By dying out of obedience to God the Father, He restores what we lost by Adam’s disobedience and through our daily disobediences/sins. We participate and are alive in Him through faith and obedience and this entails our participation in the life of the Body of Christ which is the Church - her sacraments, prayer life etc.
By rising from the dead, He conquered death for all time and the grave lost its power over us.
As Orthodox theologians however have said - the Western understandings of redemption are in no wise condemned or somehow deprecated by Eastern Orthodoxy.
Alex