What did Jesus mean when He said in Mt.10:16, 'Behold, I send you forth...?

I think this statement comes from Jesus's perspective. We are His disciples in the midst of people who always try to bring us down (i.e. atheists). Wise as serpents would mean keeping yourself smart both as a means to achieve your goals and to defend your beliefs, while harmless as doves meaning that we shouldn't be malicious towards other people in intentions.... Of course, imho.