The arrangement of celebrating the sacraments of Initiation, Easter, Pentecost and All Saints "has special significance, according to Russian Orthodox priest Father John McCuen:
“Now, the Holy Spirit has come; the church has been established, and is strengthened and guided by the Holy Spirit. Each one of us who has been baptized and chrismated [receiving the sacraments of initiation] in the Orthodox Church has received this same Spirit. So, today we celebrate the means by which we are sanctified, by which we may become saints."Father McCuen also looks at the meaning of the saints in Eastern Christianity." Read his Catholic Near East Welfare Association article to learn that meaning and more. The article concludes with two related links.
Wiki-image of Orthodox icon of All Saints is in the public domain.