Fr. Mabee completed his bachelor's degree in philosophy and linguistics, with distinction, at the University of Michigan--Ann Arbor in 2006. After teaching for two years at a Catholic school, he entered formation for the priesthood in 2008. He completed one year of priestly formation at Sacred Heart Major Seminary and then transferred, for two additional years of study and pre-theological formation, to Theological College and the Catholic University of America, where he completed the licentiate in philosophy in 2011.

He completed his theological formation and studies at the Pontifical North American College and the Pontifical Gregorian University, where he earned the S.T.B. (2014) and S.T.L. (2018), the latter in fundamental theology. He was ordained to the priesthood in 2015 and served the parishes of the Catholic Community of Flint, MI, before returning to Rome to complete his theological studies. He then went to Reading, U.K., to study for his doctorate in philosophy at the University of Reading, which he completed in 2022.

He has been in residence at Sacred Heart Major Seminary since September 2020, and is a member of the philosophy faculty and college/pre-theology formation team as of September 2021.