Religions are replete with the use of physical objects. Sometimes the point of the objects is that they are to serve as symbols. Below you can see very standard items from a Buddhist altar, specifically candles, fruit and flowers.
The candle is to symbolize the goal of Buddhism, namely enlightenment or the banishing of ignorance. Religions frequently use light for the symbolism of seeing and because anthropologically, we evolved to fear the dark.
The fruit and flowers are a bit trickier. Partly they symbolize the reward of enlightenment - its beauty, its fruitfulness. But partly they emphasize the point that while they look appealing now, they will not in a few shot weeks. This is to remind adherents of a main teaching of the Buddha - anicca or impermanence.
The Buddha felt that much suffering in life stemmed from how little we grasp the impermanence of things. No matter how horrible the sensation, it is impermanent and knowing that can provide some comfort or sanity amidst pain. Similarly, we have a tendency to want to hold on to great joys which already tinges them with sadness (for their inevitable passing) whereas accepting the fleeting nature of all things will (it is hoped) provide some serenity - savour the moment, but do not grasp for it.
Another kind of object can be found below. These not so rich in symbolism but are more about creating physical markers for our intangible hopes and wishes. These small pieces of wood are purchased and people write requests on them for blessings (for themselves or for loved ones).
They are then hung to blow in the wind where the breeze may carry the prayers. They function similarly to lighting a candle in a Catholic church. We humans like physical things. To touch, to hold, to manifest in physical form will (we hope) give some solidity to our most cherished wishes.