- Is the Catholic church or the Orthodox church the true origin church?
This question would get thrown out of any serious academic inquiry because it has methodological problems you could drive a truck through.
As I am Catholic, I would suggest that * Orientalium Ecclesiarum * is the best summary of the church’s thinking on relations with the Churches not in union with Rome, which would give one the answer for any legitimate line of inquiry along these lines.
- Who of them has the oldest and most untouched liturgy?
Neither. Both the current “Byzantine Rite” and the so-called “Traditional Latin Mass” are High Medieval redactions of earlier liturgies, one for monastic use and the other as a “shorter” liturgy for those on the Roman curia. Both of them, from what I’ve been told, are quite different in many rubrics, in church architecture, and even in some ways thought than their Late Antique predecessors.
For instance, both the Late Antique Roman and Byzantine Rite were mass-events - the bishop of Rome or Constantinople would be, in modern terms, the only celebrant, he only held it around 2 times a week beyond Sunday, and the basilicas where the Sunday liturgy was celebrated (St. Peter’s, St. John Lateran, St. Paul’s Outside the Wall in Rome, Saint Sophia or the Blachernae in Constantinople) were built to accommodate most of the people of the city. Also note that the layout of these basilicas makes no sense for the modern liturgies, but were designed for the older ones. For instance, the columns which kept the men and women separate. (St. John Chrysostom, Patriarch of Constantiople insisted on this because otherwise he thought the women of his congregation for acted like prostitutes and the nearby men for like rowdy stallions).
But if you really want to know, I’m told the “Traditional Latin Mass” mostly as seen in the 1962 Missale Romanum was promulgated by Pope Innocent III, while the Typikon and service books mostly like the current Greek editions for the “Byzantine Rite” were the approved standard in the mid-1300s. From what I’ve seen of the old Byzantine liturgy, a current Greek clergyman transported back in time and thrown into a Sunday liturgy at Hagia Sophia would be lost. (though he would understand what’s going on).
- Why do i get a more sense of holyness in the divine orthodox liturgy?
Don’t pick where you stay by how “holy” you feel. I’ve been to the “holiest” places in Greece and Italy and even there I sometimes felt bored, unmoved or the like. At the same time, I’ve felt incredibly “holy” in an airport chapel. I’ve been told God sometimes grants us great feeling in prayer. It’s wonderful, but it’s something granted at limited times for your own good. Chasing after that feeling I’m told
- Do i offend God, Lord Jesus Christ, Blessed Pope Benedict XVI, Blessed Virgin Mary and all the saints?
Neither I nor anyone else on this forum can answer that because none of us speaks for them. But if someone does, don’t believe anything they say.
Do i commit a grave sin by doubting like i do now? This has been clouding my mind for the last two weeks. I need to talk to my priest for sure, but how bad is this?
According to book Latin Catholic theology, grave sin requires many conditions, to include full consent of the will without mitigating factors (e.g. bad information in cases like this), sufficient reflection, and many other things. A priest is really the only one who can answer this.