The Saints are dear brothers who have struggled like us and have departed to Paradise. They are not dead, but are sleeping, as our Lord said (Jn 11:11) and as St. Paul called them (1 Thess 4:13).
Our early fathers spoke clearly and in detail about our relationship with Saints. The Saints in Paradise are the triumphant members of the same one church in which we are militant members. We, the triumphant and militants, are members of the Church, which is the one Body of our Lord Jesus Christ. The triumphant become invisible members because of the death of their bodies, and then militants are the visible ones. This is man's point of view, but in God's sight, we are all a visible holy family.
They departed from earth, but did not leave the church; their love toward their brothers did not cease by their departure and dwelling in Paradise. The death of their bodies does not sever the bond of mutual love between them and us; on the contrary it increases in depth and strength. Their prayers for the salvation of the entire world never cease. They pray for us, and we venerate them as they are our holy and dear friends.
We venerate the icons of saints and put them on the iconostasis. Church walls and doors are hung with icons, also our homes, etc., as a sign of our communion with them in the Lord Jesus Christ.