How can we protect secret Christians, who are scared to denounce Islam, in 3rd world countries?

Okay let's begin by not calling countries 3rd world. Then let's talk about how millions of islamic immigrants left to be drown in the Mediterranean during this last decade immigrant's wave. That is to say, we are not treating them better than they are treating us.
Traveling have taught me that, and living in Europe too.

Now, to be specific to your subject...... none should be scared anywhere in the world about anything, to be a specific religion, gender, color and whatnot. How can we protect them NOW I don't know. But how to protect these values in the long run, by beginning to practicing them ourselves, by protecting others who would not agree with our religion, and nearby. Those things aren't easy, are they ? Everyone is stepping on a thin line sometimes.

Constant prayer

There are lots to pray for. Those in Nigeria, Burkina Faso. Sudan.

Personally, I pray for the young Christian brides of North Pakistan, forced to marry into Islam.

Consistent prayer - ask for protection for them.

There are also organizations if you want to put your money where your type is.

...why, exactly? I mean, yes, freedom of religion should be a universal thing, but humanity is what it is. Wouldn't those who are in active danger now be a more logical concern than those who'll only be in trouble if they get found out?

Those having chosen falsity shouldn't be denouncing another false brand.