Islam arrived in what is now Bangladesh in the early 1200s with a military attack by Muhammad Bakhtiyar Khilji. It was an early foothold of Islam in a region dominated by the local religions collectively known as Hinduism. For hundreds of years, Muslim conquerors fought for more of Bengal, all the while facing resistance by Hindu kings. Historians are divided between those who say Hindus converted to Islam by force and those who say conversion was voluntary. In either case the result has been a region with one basic language and two world religions: Hinduism and Islam. As time progressed the two Bengali religious communities were divided not only by religion but by economics. Bengali Muslims gravitated to being landless laborers while the Hindus became landlords and urban specialists.
After India gained her independence in 1947, the Muslim regions broke away from predominantly Hindu India. A West and East Pakistan emerged, with East Pakistan eventually gaining independence from Pakistan in a brutal 1971 war. The result was the establishment of a new Bengali speaking nation called Bangladesh. This was made up mainly of Bengali speaking Muslims, though there were (and still are) members of other religious communities who speak the Bengali language. Hindu speaking Bengalis live mainly in India’s adjacent state of West Bengal. There are also millions of Muslim Bengali speakers outside of Bangladesh, mainly in West Bengal. Bengalis are the largest Muslim people group in the world.

Bangladesh is noted for economic problems, but they have grown considerably in the 2020s. With well over 100 million Bengali Muslims in Bangladesh alone, they hold any possible profession.
Yet Bengalis face an ongoing identity crisis. They are divided across religious lines, with centuries of fighting between themselves and the Hindus.

Though they are officially Sunni Muslim, Bengalis have an affinity for saints known as pirs. They believe these saints hold much spiritual power that can help one gain wealth and heal health problems. Pirs are similar to their Hindu equivalent, the sadhu mendicants. In recent decades, pirs have gained excessive political power in Bangladesh, leading some to want their influence diminished. Long after they die the graves of pirs are visited by those who want physical or material blessings.
Bengali Muslims also commonly embrace Sufism. This is a mystical and emotional Islamic practice which seeks to reach a state of spiritual purity known as fitra. Sufis form themselves into orders led by spiritual teachers.

There is a massive harvest in the making, and Bengalis are in the midst of reaching Muslims for Christ! While conservative estimates of Bengali Muslim-background followers of Christ are in the tens of thousands, some Bengali and western missionary leaders claim that a couple million Bengali Muslims have become followers of Christ within rapidly growing movements. Most of these have reportedly occurred in the 21st century.
The best things outsiders can do is regularly and faithfully pray for a complete harvest that will leave Bengalis blessed by the Lord.

Pray for the Lord of the Harvest to continue leading thousands of Muslim Bengalis to the Savior of all nations.
Pray that this largest Muslim group will find the truth of the Prophet Isa, the One who is the savior of all mankind.
Pray for the Lord to thrust out loving and steadfast workers for this neglected harvest.
Pray for Muslim background Bengali disciples to make more disciples.

Scripture Prayers for the Bengali Muslim in Bangladesh.

https://en.wikipedia.org/wiki/Bengali_Muslims
https://en.wikipedia.org/wiki/Islam_in_West_Bengal
https://www.thedailystar.net/in-focus/news/bengali-muslims-and-their-identity-fusion-confusion-2072357
https://www.linkedin.com/pulse/discovering-bengal-muslims-embracing-islam-identity-tarun-choudhury-mgnjf/
https://www.news18.com/news/opinion/the-bengal-conundrum-how-islamisation-of-bengal-started-in-medieval-times-with-forced-conversion-5138791.html
https://www.academia.edu/36873630/The_Pir_Culture_in_Bangladesh_a_sign_of_spirituality_and_secularisms
http://cyber_bangla0.tripod.com/article/article29.html
https://pure.royalholloway.ac.uk/en/publications/pirs-and-politics-in-contemporary-bangladesh-ca-1945-2020
https://en.wikipedia.org/wiki/Sufism