Hey now Stephen63... we can see it happening on a national level in the bible! Look at Ninevah.
Is it likely to occur today on a national level? One can hope... but not on a grand scale.
To the OP.
The bible speaks of a revival after the start of the Great Tribulation, which leads to martyrdom for faith and standing/abiding in God.
The bible also says that before the Great Tribulation, there will be a great apostasy, people turning from the truth of God to anything else. (1 Timothy 4:1-3)