The book Sefer Hachinuch (A great book that is written in easy to understand Hebrew that discusses the mitzvot in the parsha) talks about a particular mitzvah in Parshas Tzav. This mitzvah is that people must keep a fire on the altar in the temple burning constantly. The obvious question is: why do we need this fire constantly? Shouldn’t it only burn during the day, when we actually bring sacrifices? The Sefer Hachinuch explains this further, saying that mitzvot are designed to better a person, and the betterment is related to the actual task. What is this trait that keeping a fire lit relates to?
A trait of fire that is often discussed in Jewish literature is that it only burns upwards. This seems obvious, but when it is applied to how people behave it seems much more appropriate. The desire to grow and become closer to Hashem is an integral part of the human experience. Since we no longer offer sacrifices, the sages tell us that tefilla, prayer, has replaced it. The question that a person would have, then, is what replaces this fire that we should have burning on the altar?
When we go through our daily lives, it is easy to feel that we are self-sufficient, that we are not receiving constant help from Hashem to do all of the things that we take for granted. The commandment to keep the fire burning is now part of how our worldview should be. Jews need to be constantly aware that G-d is watching and helping us.