Guidance and encouragement
From the word go, potential mission workers should be looking for this from you. With oversight for their wellbeing, you will be called on to help them discern whether they have a missionary calling, and to where, and to do what, with which agency (if any). It’s important that as their sending church, you are part of this process, since you will be expected to endorse their mission and support them in it. Syzygy advises mission workers to consult with their church leadership at the earliest possible stage in their deliberations, since you can’t reasonably be expected to rubber stamp a decision you have not been part of making.
This input will continue throughout their missionary careers as they consult with you about the changes of assignment, location and vocation which inevitably occur. Sometimes there will be difficult decisions like whether to pull out or persevere when the going gets tough, or what to do in a crisis situation. You may not be in their situation and able to fully appreciate all the local challenges they face, but your steady and impartial advice will be valuable in difficult situations.
This means that you need to keep fully informed, by reading their regular prayer letters, and asking appropriate questions if things they write are not clear to you. You need to be praying regularly for them, not merely a simple blessing but asking God to give you guidance and direction on their behalf, and you need to be communicating regularly what you feel God is directing you to. This means that you have to keep communication channels open, as a quick email from you for the first time in three years saying you think they should come home will not be as effective as if you have regularly and consistently encouraged and guided them.
Regular encouragements using social media, snail mail and phone will be a great blessing to them. There will be many times they find things hard and the knowledge that people at home care, and have not forgotten, will help them to persevere.
This might all sound as if it’s a lot more work than you would give most of your congregation, but remember that as mission workers they are in a vulnerable situation, far from their usual home support network and will therefore be needing a lot more proactive support from the church.