Matthew begins his Gospel by recalling that Jesus, whose story he is about to narrate, is “Emmanuel” (Mt 1:23), which means “God is with us.” Matthew then concludes his Gospel by repeating these words of Jesus, his promise to remain with us always, even after he has gone back to heaven. He will be “God is with us” until the end of the age.
Jesus addressed these words to his disciples after entrusting them with the task of bringing his message to the whole world. He was well aware that he was sending them “like sheep in the midst of wolves” and that they would meet with adversity and persecutions (see Mt 10:16-22). This is why he didn’t want to leave them alone in their mission. And so at the very moment when he was leaving, he promised to stay! They’ll no longer be able to see him with their eyes, they won’t be able to hear his voice, they won’t be able to touch him, but he will be present in their midst, as he was before — even more than before. Up until then, his presence was localized in one precise place, in Capernaum, or on the lake, or in the mountains, or in Jerusalem. Instead, from then on, he will be wherever his disciples are.