Risto Jääskeläinen was born August 10, 1945, in Tohmajärvi in Finland.He has studied theology at the University of Helsinki as well as abroad in the United States (1969, 1986-1988) Hungary (1969-1970), the United Kingdom (1971-1975), and the Soviet Union in 1979. From 1969 to 1970 Jääskeläinen worked at the Orthodox Seminary of Kuopio and from 1975 to 1976 at the University of Joensuu as the vice professor.
Risto Jääskeläinen was tonsured as a monk with the name Ambrose and then ordained a hierodeacon and hieromonk in 1979 as a member of the brotherhood of the New Valaam Monastery in Heinävesi. At New Valaam, Fr. Ambrose was appointed the monastery's financial caretaker in 1977. In 1986, he received the title of archimandrite from Archbishop Paul of Finland, and from 1986 to 1988 Fr. Ambrose was the right hand man of the monastery's igumen, Archimandrite Panteleimon (now His Eminence the Most Reverend Metropolitan Panteleimon (Sarho) of Oulu).
In 1988, Fr. Ambrose was elected to be Bishop of Joensuu and consecrated to this see by Archbishop John of Finland, Metropolitan Tikhon of Helsinki, and Metropolitan Leo of Oulu. Bp. Ambrose served as Metropolitan of Oulu from 1988 to 2002, and in 2002 he was appointed to the post of Metropolitan of Helsinki.
Metropolitan Ambrose has written many theological writings, including Pyhyyden Kaipaus (1999) and Etsijän Tie (2001), and published several books concerning ecclesiastical history and ecumenical relations.