Little is known about the life of Jensen, not even the parish where he served as pastor, although his diary during the expedition provides some information. It is known that he was the chaplain aboard an expedition to the New World commissioned by King Christian IV of Denmark and Norway in 1619. The expedition was made up of two small Danish ships Enhiørningen and Lamprenen, with 64 sailors who were Danes, Norwegians, Swedes, and Germans.
Captained by the navigator and explorer, Jens Munk, the ships were searching for the Northwest Passage. After sailing into Frobisher Bay and Ungava Bay, Munk eventually passed through Hudson Strait and reached Digges Island (at the northern tip of Quebec) on August 20. They then set out across the Bay towards the southwest. By early September, they had not yet found a passage. The party arrived in Hudson Bay on September 7, landed at the mouth of Churchill River, settling at what is now Churchill, Manitoba.
It was a disastrous winter. Cold, famine, and scurvy destroyed most of the men. Only Munk and two sailors survived to return, leaving no settlement in the New World. The crew of the Lamprenen reached Bergen, Norway on 20 September 1620.
Jensen had died on 20 February 1620. Following the death of Jensen, the majority of Danish Lutheran missionary activity was concentrated in India and the Danish West Indies, especially Saint Thomas. Rasmus Jensen's commemoration date is February 20 within the Evangelical Lutheran Church in Canada and the Evangelical Lutheran Church in America.
- What happened to the first Lutheran pastor in the New World? (Evangelical Lutheran Church in America)http://archive.elca.org/communication/timeline/1619.html
- Bente, Friedrich, 1858-1930. American Lutheranism Volume 1: Early History of American Lutheranism: Lutheran Swedes in Delaware. Concordia: 1919, p.11.
- History of Lutheranism in Canada (Evangelical Lutheran Church in Canada) http://www.forministry.com/CASKLCHCASPLCS/HistoryofLutheranism.dsp
- Jens Munk - Scandinavia's First Great Polar Explorer (University Library of Tromsø) http://www.ub.uit.no/northernlights/eng/munk.htm
- Today in History(The Lutheran Church - Missouri Synod) http://chi.lcms.org/history/tih0907.htm
- Festivals and Commemorations: A Handbook to the Calendar in the Lutheran Book of Worship. by Phillip Pfatteicher. Minneapolis: Augsburg Fortress Press, 1980
- Rasmus Jensen, Pastor, With Others 20 February 1620 (Biographical sketches of memorable Christians of the past) http://justus.anglican.org/resources/bio/106.
- Project Rasmus(Evangelical Lutheran Church in Canada) http://www.elcic.ca/Project-Rasmus/Rasmouse-Tales/default.cfm
- Jens Munk Navigatio Septentrionalis, Efterretning af Navigationen og Reisen til det Nye Danmark af Styrmand Jens Munk (Copenhagen: 1624)
- Peter Lauridsen, Jens Munks navigatio septentrionalis med indledning, noter og kort (Copenhagen: Gyldendal. 1883)
- C. C. A. Gosch, Danish Arctic Expeditions 1605 to 1620, volume ii (Hakluyt Society, No. xcvii. London: 1897)