I’m sure that I’m not the only one who finds these words particularly challenging:
“Behold, I am sending you out as sheep in the midst of wolves”
Would Jesus do something so reckless as to send his disciples out without defence to certain danger? Is that the act of the good shepherd? I’ve seen it suggested that in effect the idea is that the ridiculousness of this manoeuvre would catch the wolves off guard, a surprise counterattack by creatures that are meant to run.
However, I don’t think that this is what is going on. It’s not that Jesus is sending the disciples out against the wolves. There doesn’t seem to be much of a suggestion that this is the primary Gospel strategy in the New Testament. Rather, I would suggest two things.
First of all, the point is that the disciples have a mission objective but it will take them through dangerous territory. In Psalm 23, David says that he has to go through the Valley of the Shadow of Death. He heads through danger not because the Shepherd is sending him into danger but because his journey to still waters and green pastures leads through areas where there are dangers including steep drops and pitfalls, lions, bears and wolves.
In the same way, the disciples are going out on mission. They are not being fed to the wolves. They are going to share the good news, they are going to find other lost sheep but that will put them out there amongst wolves. The point here is that we are meant to spot the characteristic traits of the creatures involved. Wolves attack, devour and destroy. Wolves are the enemies of sheep. We are in a world where there are those who hate and want to destroy the church because they hated and wanted to destroy Jesus. Yet our response is not to stop being sheep, not to become wolves.
So, what is the important thing about sheep, apart from the fact that they are not allies with wolves? The answer is that sheep are consistently dependent on the shepherd. So, when Jesus tells the disciples that they are being sent out as sheep, I believe there is an implicit promise at this stage that they are not being sent out on their own.
This is made explicit later on when Jesus says:
19 When they deliver you over, do not be anxious how you are to speak or what you are to say, for what you are to say will be given to you in that hour. 20 For it is not you who speak, but the Spirit of your Father speaking through you.
Later he goes on to say:
28 And do not fear those who kill the body but cannot kill the soul. Rather fear him who can destroy both soul and body in hell.[f] 29 Are not two sparrows sold for a penny?[g] And not one of them will fall to the ground apart from your Father. 30 But even the hairs of your head are all numbered. 
The point is that the Shepherd has not sent us out on our own or left us on our own We have a Heavenly Father who loves us and cares for us, The Son who mediates and advocates for us and The Holy Spirit present with us. The Triune God is there for us. We don’t have to defend or fight for ourselves.
As believers in Jesus we may often feel incredibly vulnerable. The church may feel like a frail and fragile response to the powers around us. If we try to do things in our own power, then that’s exactly what we will be. But Jesus is clear that it is not about us and our efforts. God is at work and we can depend non the Good shepherd.
 Matthew 10:16.
 Matthew 10:19 -20
 Matthew 10:28-30