From a very young age, Father Eustáquio showed an inclination towards priestly work. He was raised in a very Catholic family. Son of Elisabeth van de Maulenhof (1859-1931) and Wilhelmus van Lieshout (1850-1924), he grew up witnessing his mother's devotion to the Sacred Heart of Jesus and Our Lady.

In a testimony from one of Father Eustáquio's sisters, she speaks about how living in a Catholic family awakened the Blessed's priestly vocation from an early age:

“He liked going to church, and in the barn he used to play at celebrating Mass. At the age of eight or nine, he told a seminarian of his desire to become a priest as well. Farm work didn't interest him, as he thought only of the priesthood.”. (Sister Faustina)

The love for God lived within the home led Father Eustace and three other sisters to follow religious life, among them Sister Faustina, who gave this testimony about the Blessed.