Today we increasingly hear the calls to be moderate, and not venture into the extremes, and go astray. This is perfectly correct and was stressed upon by the Prophet (peace be upon him). However, a lot of people are ignorant of what moderation is, and they fall into either one of the two extremes – being so liberal that one ignores what is required or being too extreme that one exceeds the limits. Shaykh Uthaymeen, the late scholar, has explained this beautifully.
Moderation in religion means that one does not exaggerate and go beyond the limit set by Allah, and that one does not neglect it and fall short of the limit set by Allah. Moderation means following the example of the Prophet (peace be upon him). Exaggeration means trying to do more than what the Prophet (peace be upon him) did, and negligence means not reaching that level. For example, a man says, “I want to spend all night in prayer (Qiyam Al-Layl), and never sleep all my life, because prayer is one of the best acts of worship, so I want to spend the entire night in prayer.” We say, this is going to extremes in the religion of Allah, and this is not right.
Something like this happened at the time of the Prophet (peace be upon him), when a group of men got together and one of them said, “I will pray at night and will never sleep.” Another said, “I will fast and never break my fast.” The third one said, “I will never marry women.” When this news reached the Prophet (peace be upon him), he said, “What is wrong with people who say such and such? I fast and I break my fast. I sleep and I wake up to pray, and I marry women. Whoever overlooks my Sunnah does not belong to me.” (Bukhari and Muslim)
These people had gone to extremes in religion, and so the Messenger (peace be upon him) disowned them, because they overlooked his Sunnah which includes fasting and not fasting, praying at night and sleeping, and marrying women. Those who fall short say: “I do not need to do voluntary (Nafl) deeds, so I will not do them. I will only do the Fard (obligatory) deeds." He may be even falling short in the obligatory ones, so such a person lags behind in religion.
Moderate are those who follow the path of the Prophet (peace be upon him) and his rightly-guided Caliphs (Khulafaa’ Al-Rashidoon).
Here is another example: Three men come across an immoral man. one says, “I will not greet this immoral man and I will boycott him, keep away from him and not speak to him.” The second one says, “I will go along with this immoral man, greet him and smile at him. I will invite him to my place and accept his invitation. He is just like any righteous man to me.” The third one says, “I hate this immoral man for his immoral actions, but I love him for his faith. I will not boycott him unless doing so is in his best interests. If there is nothing to be gained by boycotting him, and if that will only increase him in his immorality, then I will not boycott him.” We say that the first man is being extreme, the second is deficient and the third is moderate. The same applies to all other acts of worship and dealings with others. People vary between extremism, negligence and moderation.
Here is a third example: A man is a prisoner of his wife, who directs him as she wishes and he does not stop her from committing sin, or urge her to do good. She has taken over his reason and has become the one who is in charge of him. Another man treats his wife in a harsh, arrogant and high-handed manner. He does not care about her and regards her as less than a servant. A third man is moderate in his dealings with his wife, as Allah and His Messenger (peace be upon him) commanded. “And they (women) have rights (over their husbands as regards living expenses) similar (to those of their husbands) over them (as regards obedience and respect) to what is reasonable.” (Qur’an, 2:228)
The Prophet (peace be upon him) said: “Let no believing man hate a believing woman. If he dislikes one of her characteristics he will be pleased with another.” This last man is the one who is moderate. The second one is extreme in his dealings with his wife, and the first is falling short. The same applies to all other deeds and acts of worship.
Collection of Fatwas & Letters of Shaykh Muhammad Bin Saleh Al-Uthaymeen, vol. 1, page 42.