[1] By the appointment of Vazgen I, Catholicos of All Armenians, he served as the Vice Dean of the Gevorkian Theological Seminary at the Mother See of Holy Etchmiadzin in September 1987.

In November 1989, he successfully defended his doctoral thesis entitled "The Fast in the Armenian Apostolic Church," and received the rank of Archimandrite (Vardapet).

In June 1995, Father Sebouh was appointed to serve as the Director of the Reserve Stewardship Inventory Committee of the Armenian Church.

[10][11] However, according to some experts, the Armenian Community of Turkey was inclined to elect Bishop Sebouh Chouldjian (citizen of Armenia) as their spiritual leader[20] which was disallowed by the Turkish government after unsuccessful negotiations of Armenia-Turkey reconciliation.

"We continue to hope that this is not the manner of actions of Erdoğan's government, but that of the stationary state sub-agencies, which hamper the democratic development of Turkey with their old mentality".

[22] Bishop Sebouh said it was the moral obligation of Archbishop Aram Ateshian to send a new letter to the Turkey's Government with request to hold the elections of Co-Patriarch.

[37] On 27 September 2019 Archbishop Sebouh Chouldjian released a statement requiring from the Turkish government to restore the original text of the 25th clause of canonical regulation which was violating the rights of bishops from outside Turkey.

On 5 December 2019 Archbishop Sebouh released an official statement regarding the election of 85th Armenian Patriarch of Constantinople, indicating that he "forgives everyone", who caused his disentitlement.

He said: "It is now beyond any doubt, that the reason for the staging of the "canonical change" was myself, since the support for me by a significant portion of faithful Armenian people in Turkey could be decisive".

He condemned this as an outrageous historical injustice and indirectly pointed out the nefarious role of Archbishops Sahak Mashalyan and Aram Ateshian.

[44] On 24 March 2009, Prime Minister of Armenia Tigran Sargsyan warmly congratulated Archbishop Sebouh on the occasion of the 50th anniversary of birthday.

In his message he emphasized Bishop Sebouh's input in organizing Christian education, revivification of church life and restoration of ethnic and spiritual identity of the Armenian nation.