The problem with materialism is that it arrests our attention, constantly, to care for material things: my home, my car, my TV, my work, my golf game, my dinner party. These things—none of which are wrong in and of themselves—can nevertheless distract us from our principle concern: the salvation of our immortal souls.
If we are too preoccupied with material things, then we are not going to pay enough attention to our spiritual life, which requires detachment from things so that we can attach ourselves to God. The Lord has given us much for which we are most grateful. However, let us not amass our treasures here below. Rather, let us seek to be “rich in what matters to God.”