A verse in the Quran says: "Believers, fasting has been prescribed for you, just as it was prescribed for those before you, so that you may guard yourselves against evil." (2:183)
Fasting was observed by previous communities as well, and not only the Muslim community. In other words, fasting had been prescribed for communities of all the messengers sent by God. 

This tells us about the universal significance of fasting. Fasting is very important. If it were not so, why were communities of all the prophets asked to observe fasting?
I reflected a lot this and came to a realization. We eat and drink on a daily basis. When we feel hungry we eat, and when we are thirsty we drink water. In a way, we usually lead a life expressed by this saying: 'Eat, drink and be merry.' During fasting, we are required to abstain from food and drink. Why so? This helps you to think that life is more than just eating and drinking. There is a greater purpose to life. Besides eating and drinking, there is a goal or purpose to be fulfilled. 
You should realize, 'There should be something else in life.' You must think: 'My life is deeper and I should have a higher goal.' 

What is that goal? That is leading a purposeful life, developing a relationship with God, discovering deeper realities and adopting spiritual values. You are required to abstain from food and drink to create a compulsion that makes you think: something else is required in life. There should be a goal apart from eating, drinking and being merry. This is why fasting had been prescribed for all communities. Food and drink are a person's necessities and physical need. We will die without them. A person eats when hungry and drinks when thirsty. This is how he leads his life on a regular basis. So, he feeds only the physical side of his personality. Fasting informs us that we have another side to our personality, which is the spiritual side. We need to give ourselves spiritual sustenance as well. 

We generally do not feed the intellectual side of our personality. In truth, people spend their lives focusing on their physical side. This is why fasting has been prescribed in one month of the year. For eleven months, we feed the physical side of our personality. The other side of our lives is the intellectual and spiritual. We need to feed that as well. Fasting has been enjoined to develop this way of thinking in us.