Question: "What does the Bible have to say about women missionaries?"
Answer: First Timothy 2:11-12 declares, “A woman should learn in quietness and full submission. I do not permit a woman to teach or to have authority over a man; she must be silent.” This clearly precludes women from serving as teaching pastors over men. But how does it impact women serving as missionaries and/or evangelists? Does it mean women should not be involved in any sort of evangelism and/or missionary work towards men?
It is very important to note that the Bible nowhere restricts women from sharing the gospel. The exhortation to evangelize is directed towards all followers of Jesus Christ (Matthew 28:18-20; Acts 1:8; 1 Peter 3:15). The restriction in 1 Timothy 2:11-12 is in regards to church-shepherding (teaching and exercising authority) roles over men. It does not apply to evangelism. No woman should ever feel biblically restricted from sharing the gospel with a man.
Further, the Bible describes women serving in many roles that are crucial in missionary work. Women are encouraged to teach other women (Titus 2:3-5). Women are to be dedicated to prayer (1 Corinthians 11:5), exercising the fruit of the Spirit (Galatians 5:22-23) and the gifts of the Spirit (1 Corinthians 12). The vast majority of missionary work is undeniably open to women. The question arises, though, as to whether there is any missionary role in which women should not serve.
If at all possible, women missionaries should not serve as pastors/shepherds over men. In an instance where there is no man willing or able to take leadership, perhaps then a “Deborah principle” applies. In Judges 4-5, Deborah encouraged Barak to take leadership of Israel’s armies, but he was unwilling. Therefore, Deborah took the leadership role. If on a mission field, there is no qualified man to shepherd new believers, it does not seem God would desire those new believers to remain undiscipled until a man arrives. But a woman serving a shepherding role in an instance like this should do everything she can to quickly build and develop male leadership to take over the shepherding of the men in the church.
Remember, though, that this would be an extremely rare exception. Further, it is not explicitly biblical, but rather speculative. In no sense would this exception, even if it was definitively biblical, disprove the clear message of 1 Timothy 2:11-12.
Due to the inherent dangers of missionary work, and due to the sexism that is dominant in so many cultures, it is usually best for women not to serve as missionaries on their own. Husband and wife teams and/or teams of women partnering with men and/or other women, seem to be the best setup for missionary work. But in no sense should this discourage women from missionary work. God calls women, single and married, to serve Him on the mission field. And God often uses women missionaries in powerful and amazing ways.