I asked the same question. This is the answer they gave me:
PART ONE:
In the Name of Allah, The All Merciful, The Most Merciful.
Rasulullah SAW said, "…And the gates of Heaven will be open in this month and the gates of Hell will be closed. And the devils will be chained." [Musnad Ahmad]
According to this Hadith, we come to know that one of the greatest blessings of the month of Ramadan is that Shaitan will be chained. He will not be able to lead us astray in this blessed month. So, the common question arises: If Shaitan is chained and unable to influence us, then how do we still commit sins in Ramadan?
Let us analyze this Hadith insha'Allah. When Rasulullah SAW says that the devils will be chained, it does not mean that the devils will be slain. If we come across a lion, there is a high chance that the lion will chase us, and we will be killed. But if the lion is chained, then we are safe from it. Yet, if we go too close to the lion, there is still a high chance that we will be killed even if he is chained. So, we are only safe from the lion if we maintain a safe distance.
In the Qur'an, Allah does not tell us to just simply not listen to the Shaitan. But Allah always says to the believers to be careful of the footsteps of the Shaitan. If the Devil comes in front of us to lead us astray, surely we will be very cautious. However, the method Shaitan uses to lure the believers into wrongdoings is that he leads us to a trap by making his footsteps tempting. For example, fornication outside of marriage is not the footsteps of the Shaitan because believers will always be careful of that sin. Rather, exchanging phone numbers and intermingling are the footsteps of the Shaitan that can eventually take us to the trap of fornication.
Brothers and sisters in Islam, we must always be cautious of the footsteps of the Shaitan. In Ramadan, Shaitan will not be able to come to us and lead us astray Alhamdulillah. But if we still choose to follow the footsteps of the Shaitan straight into his grasp, even when he is chained like the dangerous lion, Shaitan will definitely be able to control us even in Ramadan. But if we fast and stay away from his footsteps, we will find that it is much easier to stay away from evil deeds.
"O you who have believed, do not follow the footsteps of Satan. And whoever follows the footsteps of Satan - indeed, he enjoins immorality and wrongdoing."
[An-Noor (Light) 24:21]
PART TWO:
In the Name of Allah, The All Merciful, The Most Merciful
Rasulullah SAW said, "…And the gates of Heaven will be open in this month and the gates of Hell will be closed. And the devils will be chained." [Musnad Ahmad]
The last time, we looked at one of the reasons why Muslims continue to sin in Ramadan even though Shaitan is chained. It was noted that, although Shaitan is chained in Ramadan, if we follow his footsteps (small acts leading to any sin), Shaitan will still have control over us. This time we should look at another reason why Muslims continue to commit sins in Ramadan.
One important detail we should realize is that if the Devil is chained in Ramadan, he is still free the other eleven months. If we indulge in distasteful behavior in those eleven months, the impact Shaitan has on our hearts leaves an imprint in the month of Ramadan.
We should look at drug dealers as a comparison. In most cases, drug dealers go out of their way to find large numbers of youngsters. In the beginning, the dealers distribute drugs to the youngsters absolutely free of charge. Later, the drug dealers charge a nominal fee, and they increase the intensity of the drugs. After more time passes, the dealers start to charge a very high fee, and they distribute even stronger drugs to the youngsters. But by this time, the youngsters have become addicted to the drugs. So even if the dealer is imprisoned, the youngsters will either go looking for him, or they will find another supplier to satisfy their evil addiction.
Brothers and sisters, although Shaitan is chained in Ramadan, if we follow his footsteps and become addicts of his evil ways in the other eleven months, we will continue to commit the same sins in Ramadan. It is as if we go looking for the supplier of our evil habits, the Shaitan, even though he is imprisoned by Allah. The cure from this addiction is fasting with the sincere intention of pleasing Allah SWT. After all, Ramadan is a mercy for all of mankind. Alhamdu lillahi Rabbi Al Alamin.