Before the chrismation in the Orthodox Church I had been "Unofficial Orthodox" (as I used to call myself)more or less 5 years. I'd been fasting and attending Liturgies and services, some Orthodox meetings, pilgramages, etc. However, after being received into Orthodoxy, I feel absolutely different, because, obviously, Orthodox is not only attending services and observing some rules I couldn't even image how big would be the difference.
First of all, the participation in the Holy Mysteries, especially Eucharist. That I'm truly a part of the Mystical Body of Christ - the Holy and Apostolic Church. Without heresies, changes in the ancient Christian faith. I also feel true member of parish, of the community. I have more spiritual talks with my priest. I can develop myself in the way I couldn't before the chrismation (there was important not only the fact of receiving into the Church, but also the chrismation itself - the gifts of the Holy Spirit).