"Safety is not our priority," David Platt has said. This is a fairly common refrain these days - the need for believers to be bold.
It's a good challenge, but it must be tempered: as with anything, too much of a good thing can be bad.
We get the word martyr from the Greek martys. It's used 34 times in the New Testament--but only twice does it refer to witnesses who die (Acts 22:20, Revelation 17:6). In nearly every instance the reference is to those who are observers of events or legal witnesses. In fact, in Acts 7:58, the martys are those who stone Steven.
We are called to be willing to lay down our lives for the sake of Christ (Luke 9:24-26, among others). At the same time, while the Bible records one instance of a martyr (Steven), it records numerous instances of God rescuing witnesses (notably Peter in the jail cell and Paul's multiple rescues).
We glorify martyrs and the idea of dying for a cause. Living wisely for a cause is harder. We remember Jim Elliot, and his sayings become passionate quotes - and indeed, in the case of Elliot, after his death things worked out well and the tribe came to faith. But there have been many times when the church has been killed off and people have not come to faith (or at least, not yet).
If the "blood of the martyrs were the seed of the church" in every instances, Morocco to Pakistan would be indelibly Christian by now. Such is not the case. Central and Southern Asia - all of the -Stans - have persecuted the church horribly, killing believers in every way imaginable (and some I would never have imagined), and the church remains an infinitesimally small percentage.
I do not say these things as a "downer" or to suggest that church growth cannot happen in this regions. I say these things to say that a glorious death does not always result in an enduring witness. In most cases, only an enduring witness is an enduring witness.
In the case of Elliot, Jim died--but if it hadn't been for the grace, forgiveness and continued work of his wife Elizabeth among the Huaorani, the tribe would have probably been lost.
Boldness is required - and so is wisdom. Personal safety may not be our priority, but sustainability of the witness should be--if not the priority, then certainly pretty high up there.