Baptized in the Catholic church as an infant, Even as a very young child, Mattie was deeply spiritual and said that his purpose on earth was to serve God as a messenger, shaping and sharing words of hope and peace for people all around the world.

Mattie enjoyed attending Mass several times a week, and received the sacraments of First Reconciliation and First Holy Communion when he was 7 years old. After conversations with his Archdiocesan Cardinal and parish pastor, Mattie was encouraged to study for the sacrament of Confirmation which he received at 8 years of age. 

Also at the age of 8, Mattie began serving as a Minister of the Word (Lector), reading from the Bible during weekday and Sunday Masses. A year later, he began teaching CCD (Sunday School) lessons to 2nd graders, and at age 11, he began teaching the 6th grade CCD class. Throughout his life, he was an active participant in his church community — joining the choir and serving as a greeter and his parish’s “designated hugger.”
 
Many of Mattie’s poems and essays reflect his friendship and conversations with God.  Even as he studied and respected world religions, Mattie embraced Catholicism and said that his life and spirit were strengthened by communion with the Saints and in receiving the Holy Eucharist. He also had a deep reverence for Mary, and her joy in saying “Yes!” to God and for her “quiet but ever-present maternal support” for her Son, Jesus. Mattie’s final request in life, the day before he died, was to receive the gift of reconciliation and to celebrate the gift of Holy Communion.

Mattie felt very connected to a number of saints, including St. Jude Thaddeus (a person of hope for whom Mattie chose his confirmation name), St. Francis of Assisi (a person of peace and gentle strength), St. Anthony (a person who shared messages of love and who helps with lost things and people), and St. André Bessette (a person who exemplified resilience in medical and family challenges during in his youth and who exemplified purposeful devotion and service throughout his life). Mattie believed he received a miracle from (then) “Brother André” during the summer of 2001, which he said gave him the gift of “a few more years to serve God with purpose — sharing the message of “Heartsongs.” (Brother André was declared a saint in 2010, six years after Mattie died).

Although Mattie was a devout Catholic, he also served as a volunteer in other spiritual communities — sharing messages of hope and peace with diverse communities or helping with specific activities and events. He embraced opportunities in writings, speeches, media appearances, and personal conversations with local and global neighbors to express his respect for the diverse faiths of  people around the world, and to remind youth and adults that we are all children of one God. Mattie believed that God creates and loves all people, and that messages of hope and peace are gifts to be offered to everyone.

Mattie believed that we are each born with a “Heartsong” — or a reason for being and a purpose in life. He shared and celebrated that “Hope is real, peace is possible, and life is worthy!” — if we each choose to embrace such truths in attitude and action, for ourselves and for all people in our world.

Mattie envisioned a world at peace, and he saw humanity as a “mosaic of gifts — to nurture, to offer, and to accept.” He said “peace is possible” and that while ending war matters, “peace begins within each person when we our basic needs are met.” He said that when we have access to what we need to survive — food, water, shelter, healthcare… — and also access to what we need to thrive — education, trust, purpose, hope — then we are able to choose to be “okay with who and how we are as a person.” When we are able to be okay with who and how we are, we can then choose contentment and gratitude, and turn our thoughts and attention and resources outward, and tend to the needs of others — “our neighbors around the block and around the world” — so that despite differences, they, too, can be okay with who and how they are as people.

In 2002, Mattie shared what he called the “Three Choices for Peace” – a “Pathways to Peace” guide for how to move forthward in life, with personal peace that grows into world peace.

Mattie’s philosophy for life — which he first expressed at age 5 — was“Remember to play after every storm!” and his motto was “Think gently, speak gently, live gently.” 

Mattie wanted to be known, and remembered, as “a poet, a peacemaker, and a philosopher who played.”