I think each of us must decide this one for himself or herself. But some things can be said quite solidly.
1. Healthy life requires meaning. Whether we believe that we each create meaning, or we each find different meanings, or there is one great meaning for all of us doesn't matter. But finding or creating healthy meaning is a part of leading a healthy life.
2. A grand scheme does not require a schemer. (I respectfully disagree with Dan Barfield here.) There is a beautiful notion of "The web that has no weaver," and Gregory Bateson suggests "the pattern that connects is a metapattern." That grand scheme, or metapattern, that gives all other things and schemes a place and meaning might be an intelligence with no creator, a self-existent reality. If seen, it is called Divine. If personified, it is called God.
3. It seems that it is always possible to find a pattern and meaning deeper than any pattern and meaning we know. Even in chemistry and physics: exploring the nature of substances led to chemistry, which lead to the pattern called molecules, then the pattern called atoms. Then, below that, the patterns of subatomic physics. Then quantum mechanics. And now, beyond that, to String Theory and the existence of forms larger than the Universe that give birth to tiny subatomic particles. Similarly, we start with feelings and thoughts, and psychology explores the individual, sociology explores community, economics explores practical relationships, history explores communities over time, we develop notions of human purpose. Then we see connections between people and animals, and plants, and how we all live within ecosystems and how all Earth is one ecosystem interacting with the physical solar system, dependent for life as we know it, certainly, on the sun and the moon and the absence of certain stellar events too close for comfort.
4. If we believe that there is a grand scheme, we don't have to know what it is. We only need to know the rightness of our own place in it, and the scheme for our own lives, to have a very fulfilling life. In fact, we can miss out on life searching for the grand scheme.
5. If there is a grand scheme, we are part of it.
For me, it works very well to see the grand scheme as a dance. It is more important for me to dance my part in the dance than it is for me to see the pattern of the whole dance.