The question, “what is the meaning of life,” is a very human question.
We ask ourselves this question because we want to better understand the world around us. In particular, we want to know whether there is some deep and underlying reason or purpose for our life, for our existence as persons capable of making choices and pursuing ends.
We’re asking whether there is some deeper, underlying purpose to the existence of human kind; some underlying reason why we're here in the first place, a task or activity we're supposed to accomplish, a truth we're supposed to discover.
Saint Thomas Aquinas addresses this question in the first five questions of the First Part of the Second Part of his Summa Theologica, drawing both from philosophy and theology. Our existence, he argues, is a gift of love from the source of all existence: Ipsum Esse Subsistens, Subsistent Being Itself. According to Saint Thomas, we are created by the God who is love, for friendship with this God and with all other creatures. For Saint Thomas, this frames the overall context of our existence and the existence of every creature.
Saint Thomas believed our purpose can be narrowed down through a careful examination of our human nature. From the constitution of our intrinsic desires, he argued that we cannot be truly or ultimately satisfied by wealth, honor, fame, power, health, strength, pleasure, virtue, or any created thing.
Saint Thomas argued that the ultimate purpose of every human life is what he called the Beatific Vision, perfectly seeing and loving the God who is goodness and love itself, in the community of all those who also love God. This present life, according to Saint Thomas, is a kind of test in which we have the opportunity to choose freely whether to love God and neighbor and how much to love them. The more we love in this present life, he argued, the happier we will be in the Beatific Vision.
By contrast, the more we choose selfishness and pride the more miserable we make ourselves, not only in the present life but also in the life to come. Hence our choices are meaningful, because they have everlasting effects, whether beneficial or harmful, both in the lives of others as well as in our own – therein is Saint Thomas's answer to our earlier question. What is the ultimate purpose of our lives, and the purpose of all the sacrifice and suffering we endure? We are made for love.