Which includes not engaging in missionary activity:

Christians can continue living safely in the Gaza Strip only if they accept Islamic law, including a ban on alcohol and on women roaming publicly without proper head coverings, an Islamist militant leader in Gaza told WND in an exclusive interview.
The militant leader said Christians in Gaza who engage in “missionary activity” will be “dealt with harshly.”The threats come two days after a church and Christian school in Gaza was attacked following the seizure of power in the territory by the Hamas terror group.
“I expect our Christian neighbors to understand the new Hamas rule means real changes. They must be ready for Islamic rule if they want to live in peace in Gaza,” said Sheik Abu Saqer, leader of Jihadia Salafiya, an Islamic outreach movement that recently announced the opening of a “military wing” to enforce Muslim law in Gaza.
Jihadia Salafiya is suspected of attacking a United Nations school in Gaza last month, after the school allowed boys and girls to participate in the same sporting event. One person was killed in that attack.
[…]
Abu Saqer accused the leadership of the Gaza Christian community of “proselytizing and trying to convert Muslims with funding from American evangelicals.”
“This missionary activity is endangering the entire Christian community in Gaza,” he said.
Abu Saqer claimed there was “no need” for the thousands of Christians in Gaza to maintain a large number of institutions in the territory.

Missionary activity is Christianity. The church is commanded to make disciples of all the nations:

Matthew 28:19 Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, 20 teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”

Please join me in praying that the Lord will enable them to find a way to proclaim the gospel of Jesus Christ even in this dangerous situation.