Aaberg em­i­grat­ed to Amer­i­ca in 1901 and went to the small, close-knit Dan­ish-Amer­i­can com­mun­ity in Min­ne­a­po­lis, Minneso­ta, to join his bro­ther, who was then stu­dy­ing for the min­is­try at Augsburg Coll­ege and Sem­in­a­ry. After attending St. Ans­gar's Coll­ege, and Grand View Coll­ege and Sem­in­ary in Des Moines, Iowa (1904-1908), he married Else Katrina Raun in 1908 in Wisconsin.

Following, he was or­dained in the Danish Evan­gel­i­cal Lutheran Church in Amer­i­ca. He pas­tored in Mar­in­ette, Wiscon­sin; St. Peter's Lu­ther­an Church, Dwight, Il­li­nois (1912-1926); and St. Pe­der's Luther­an Church, Min­ne­a­po­lis. Un­til re­tir­ing in 1946, Aaberg con­tin­ued to serve as pas­tor of St. Peder's. Over the years he held var­i­ous of­fic­es through­out the Danish Evan­gel­ic­al Lu­ther­an Church in America, and for years af­ter his re­tire­ment served a ser­ies of con­gre­ga­tions around the country as an in­ter­im pas­tor. In 1947 he was honored with the Knight Cross of Den­mark from King Fred­er­ick for ser­vice to Dan­ish-Amer­i­cans.

Aaberg trans­lat­ed some 80 hymns and songs from Dan­ish to Eng­lish, and served on com­mittees which com­piled sev­er­al Luther­an hymnals. He be­gan translat­ing hymns in ear­nest after an in­ci­dent that oc­curred while he was in Mar­in­ette. A Lutheran bi­shop from Den­mark at­tend­ed church there one Sun­day on a trip to Amer­i­ca. In hon­or of his vi­sit, the Marin­ette con­gre­ga­tion held a spe­cial fes­tiv­al wor­ship service. Af­ter the service, Aa­berg asked the bi­shop what he thought of the ser­vice this little con­gre­ga­tion had just held. The bi­shop re­plied, "It was so won­der­ful. It re­mind­ed me of the way church ser­vices were in Den­mark 50 years ago."

That com­ment, meant as a com­pliment, stirred Aa­berg. He conclude­d that to be vi­tal and liv­ing Christ­ian congregations, the Dan­ish-Ameri­can Lu­ther­an Church must begin to use the lan­guage of Amer­i­ca, Eng­lish. Stay­ing strictly with Dan­ish, he be­lieved, the church would be­come an ev­er more iso­lat­ed back­wa­ter of nos­tal­gia for the past. He began the work of creat­ing and pub­lishing trans­la­tions. A hymn trans­la­tion com­mittee was formed, con­sis­ting of Aaberg and three other like-mind­ed pas­tors. They met some opposition and un­hap­pi­ness to­ward their trans­lat­ing work. Some with­in the church felt that by trans­lat­ing these hymns to Eng­lish, the trans­lat­ors were has­ten­ing the day when the Danish Lu­ther­an tra­di­tions would be lost. But the work went for­ward, through the years be­tween the World Wars, un­til most of the trea­sured hymns had been trans­lat­ed to Eng­lish.

http://www.hymntime.com/tch/bio/a/a/b/e/aaberg_jc.htm