Is the one who does not get married a sinner?
Marriage becomes obligatory- according to the majority of the scholars- in one condition, and that is if the man or the woman is scared of committing fornication if they do not get married. Then it is incumbent on the person who has the financial and moral ability to get married, should get married if he needs it, and he is afraid of the consequences of his desires in what is forbidden. If one is unwilling to have sex, and is capable to control himself, whether man or woman- then marriage is not obligatory on such, according to the majority of the scholars unless this becomes the general trend.
According to Zahiris’ who differed from the majority and said it is obligatory to get married for everyone who is able to, irrespective of whether he needs it or he does not.
The truth is with the majority of the scholars, for we have seen quite a lot of Imams of knowledge and masters of the religion, who have abandoned marriage and lived as singles. The scholar Abdul Fattah Abu Ghuddah has written a book about these kinds of people, which he called “The single scholars who preferred knowledge to marriage”
But it is important to understand why these scholars did not get married. They did not get married, because they saw it as a material and moral cost that would hinder their achievement. They saw that marriage distracts from knowledge, takes a part of their time, and makes them to become coward and miserly, and they saw it a big distraction from knowledge to which the devote their lives to.