One of my colleagues has left the congregational and Friday prayers because he has to take off his shoes before entering the mosque. Because of that, for the last year, he has been praying the Thuhr prayer at home instead of the Friday prayer, and he prays the daily prayers at home or in the workplace. When we asked him about this, he said that he referred mostly to the following two hadiths:
1) “Be different from the Jews, who do not pray in their shoes or in their leather slippers.” [Abu Dawood, 652]
2) Abu Sa‘eed Al-Khudri said, “While the Messenger of Allah, sallallahu ʻalayhi wa sallam, was leading his Companions in prayer, he took off his shoes and placed them to his left. When the people saw that, they took off their shoes too. When the Messenger of Allah, sallallahu ʻalayhi wa sallam, finished his prayer, he asked, ‘What made you take off your shoes?’ They said, ‘We saw you take off your shoes, so we took ours off too ... his shoes, let him wipe them and then pray in them.” [Abu Dawood, 650]
He tried washing his shoes before entering a tiled mosque a few times, but the other people objected to this, so he stopped going to the mosque. We have tried to make him understand that it is permissible to pray with one's shoes inside the mosque, but that it is not obligatory, as the mosques nowadays are carpeted and have tiles fitted, which may be stained and may be the cause for other worshippers' hardship, but this did not satisfy him, and he said that if he enters the mosque while taking of his shoes, he might go out of the fold of Islam as it would make him imitate the Jews. So we asked him what would satisfy him so that he would enter the mosque, and he said that he is searching in the Quran and hadiths and that if he found a direct reference from the Quran and hadiths which refers to entering the mosque while taking of one's shoes, he will enter the mosque barefoot. We have tried to convince him in every possible way, but we have failed to do so. So how can we go ahead in this regard? A direct answer is expected in order to make him understand.

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ʻalayhi wa sallam, is His slave and Messenger.

It is strange indeed that a Muslim would refrain from praying in the mosque and miss the Friday and congregational prayers under the pretext that if he took off his shoes he would be committing disbelief! Does he pray at home with his shoes on so that he would not commit disbelief? How saddening the situation of many Muslims nowadays is! They are lost in ignorance and falsely ascribe it to the religion.

As to how you could convince him, then let him know it was authentically narrated that the Prophet, sallallahu ʻalayhi wa sallam, took off his shoes and performed the prayer barefoot inside Al-Masjid Al-Haraam. ʻAbdullah ibn As-Saa’ib, may Allah be pleased with him, said, “I was with the Messenger of Allah, sallallahu ʻalayhi wa sallam, on the day of the Conquest (of Makkah). He prayed in front of the Kaʻbah. He took off his shoes and placed them on his left and started to recite Surat Al-Mu’minoon. When he reached the passage that mentions Moosa (Moses) and ʻEesa (Jesus), may Allah exalt their mention, he started coughing, so he bent for the bowing.” [An-Nasaa’i and others]

Moreover, Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet, sallallahu ʻalayhi wa sallam, said, “When any of you prays and takes off his sandals, he should not harm anyone by them. He should place them between his feet or pray with them on.” [Abu Daawood] Abu Hurayrah also narrated that the Prophet, sallallahu ʻalayhi wa sallam, said, “When any of you prays, he should not place his sandals on his right side or on his left so as to be on the right side of someone else, unless there is no one on his left; he should place them between his feet.”

This clearly proves that it is not obligatory to perform the prayer while wearing shoes. Abu Daawood allocated a chapter in his book Sunan Abu Daawood entitled, “Chapter: Where should the person performing the prayer place his shoes if he takes them off?”

Allah knows best.