All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Muslim scholars haven`t disagreed on the permissibility of praying between pillars if there was a need for that. For example, the Masjid was too small to accommodate the praying people. They haven`t also disagreed about the permissibility of praying there in a row alone or as an Imam. Rather, they have disagreed on praying behind the Imam in rows divided by pillars although the Masjid is spacious.
Therefore, some of the scholars disliked that; whereas, others considered it permissible. Nevertheless, it is imperative that this doesn`t incite sedition amongst the praying people, and that they avoid dwelling on it. On their part, the people of knowledge have agreed that it is prohibited to object to an iniquity if that leads to a greater iniquity. In addition, it is a priority to prohibit objecting to reprehensible matters or issues of disagreement if that leads to dispute and conflict in Masjids. However, Muslim scholars have stated that it is permissible for people to pray behind the Imam in rows divided by pillars. This is because Al-Imam Al-Ramli was once asked: "Is it disliked for a person to perform prayer between two pillars in the Masjid? He replied: "No, it isn`t, whether he was praying alone, an Imam, or praying behind the Imam. " {Fatawa Ar-Ramli, vol.1/pp.232}.
On the other hand, scholars who considered praying in rows divided by pillars reprehensible based their view on the Hadith narrated by AbdulHamid ibn Mahmud who said: "I offered the Friday prayer along with Anas ibn Malik. We were pushed to the pillars (due to the crowd of people). We, therefore, stopped forward and backward. Anas then said: We used to avoid it (setting a row between the pillars) during the time of the Messenger of Allah (PBUH). {Related by Abu Dawoud and Tirmizi}. Atirmizi graded this Hadith as Hasan.
However, some scholars disliked that people pray in rows divided by pillars, and this position was adopted by Imam Ahmad and Is-hak; whereas, some scholars considered that permissible." The above Hadith could be referring to what the companions used to avoid during the time of the Prophet (PBUH): non-straightening of rows, and not prohibiting praying between pillars because division of rows is exempted since the Prophet`s pulpit divided the first row of his Masjid (PBUH), and he (PBUH) performed prayer between the two pillars inside the Kabah, as related by Bukhari (May Allah be pleased with him). Moreover, Mohammad Bin Sirene considered praying between pillars permissible. This was narrated by Ibn Shaibah in {Al-Mosanaf, vol.1/pp.222}. In conclusion, no matter what the case maybe, this is a matter of disagreement, so it shouldn`t lead to dispute among Muslims. And Allah Knows Best.