Spoilers: Vaguely for Season 4
That faith carried him through her death when he was twenty, a cancer that proved to be inoperable and resistant to even the harshest chemotherapy treatments. Through it all, Sarah Beth remained positive and strong, helping others on her ward floor until she became too weak to do so. She died late one night, Matthew at her side, a faint smile on her lips as she looked past him, her eyes focused on something beyond his comprehension.
Many would have turned bitter, but Matthew believed that his mother had gone to a better place and was glad of it; she was beyond suffering, and though he missed her, he knew he would see her again some day.
He graduated college with a degree in structural engineering and went to work for a firm that went to communities after natural disasters and helped rebuild the infrastructure of the area. It was good work, worthwhile, and he had the chance to see God's work in action, both His might and His compassion as he witnessed minor miracles that compounded his faith that everything that happened did so for a reason.
He was in his early thirties when the dreams began, vivid flashes of light and rushes of wings, a cacophony of voices murmuring words just beyond his understanding that left him feeling incomplete and aching when he woke. His current relationship, with a woman named June who worked at the local day care center, ended as he grew more and more distracted by the things he could almost see as he slept, the purpose that dangled just out of his reach.
Exhausted and disoriented, he took a leave of absence from work, wanting time to think, to pray, to try to understand what was happening and why. Entering his apartment, he dropped into a chair, not even bothering to strip off the trench coat he wore in deference to the cool mountain autumnal air. He closed his eyes, folded his hands in his lap, and began to pray for guidance. Somewhere along the way he fell asleep - and the voices resolved into one, one speaker telling him that he was needed, that he would host an angel come to earth to battle the forces of Hell and save the world from the dominion of Lucifer.
He was needed, if he would agree.
And Matthew Carter said yes.