Fintan received his religious formation under the Abbot Colum, and was deeply influenced by his penitential practices and the severity of his Rule.
[3] Fintan gave his monks very strict rules not to consume any animal products.
A deputation of local clergy headed by Canice of Aghaboe came to urge him to improve it.
[3] Fintan was reported to have lived on only "bread of woody barley and clayey water of clay".
[7] Fintan of Clonenagh is regarded as one of three patron saints of county Laois which include Colman Mac ua Laoise and Mochua of Timahoe.