Some Christians are unjustifiably skeptical of putting deep thought into their faith. This stems from misunderstanding key Bible passages, in this case, we’ll look at Matthew 10:16-20. I’ve written a lot about this passage, but with regard to being wise like serpents.
Let’s read the passage:
16 Behold, I am sending you as sheep in the midst of wolves. Therefore, be as wise as serpents and as innocent as doves. 17 Now, beware of people. For they will hand you over to the Sanhedrin, and in their synagogues they will flog you; 18 then they will bring you before rulers and kings because of me in order to be a testimony to them and the nations. 19 Now, when they hand you over, do not be anxious over how you will speak or what you will say; for what you will say in that hour will be given to you. 20 For you are not the ones speaking, but the Spirit of your Father speaks by you. (Matthew 10:16-20) 
A Course Correction
I’ve heard this passage interpreted to mean that “the Holy Spirit will give you what to say and not to think about what to say when you share the gospel” several times.
But here are some points from the passage and elsewhere in the Bible that give us a more well-rounded point of view:
- In Matthew 10:18, the disciples will be a testimony. In the New Testament, that word is typically used to mean testimony to the facts of the case regarding Jesus. In other words, Jesus expects his disciples to communicate his message to these people.
- Jesus says, “do not be anxious over how you will speak or what you will say.” This is not the same thing as saying, “do not think.” Do not be anxious means, do not obsess over it to the point of not making any decision to speak (see how Matthew 6 shows that Jesus’ teaching on anxiety about tomorrow assumes that his disciples will be working and planning for tomorrow).
- Finally, in John’s gospel, Jesus says that the Holy Spirit will “remind you of everything which I said to you. (John 14:26)”
In context, it appears that Jesus can tell his apostles this precisely because they have been putting thought into how they will speak the whole time they’ve been with him. Not only so, but elsewhere, the Holy Spirit is said to help remind Christians of Jesus’ teachings. So in that sense, the disciples time with Jesus preparing. I’m not trying to say that there isn’t a prophetic element in the passage, but as I pointed out in #2 above, Jesus’ pattern for overcoming anxiety starts with observing the birds and comparing how they have food despite not sowing, reaping, and storing to our own circumstances. If we are doing what we ought, there is no reason to be anxious. Similarly, if Jesus’ disciples are doing as they ought, and memorizing, internalizing, interpreting, discussing, and synthesizing his teachings, they won’t need to prepare lengthy court defenses when asked questions like, “What are you doing/saying/teaching? Explain yourself for contradicting Torah. Why don’t you do the Sabbath? etc.”
Any interpretation of Scripture which claims that reflection about your life or about the gospel should be viewed with skepticism. Frequently, I think, the incorrect interpretation of Matthew 10:19 is used as a spiritual cloak for intellectual laziness, but I hope I’m wrong.
 Kurt Aland et al., Novum Testamentum Graece, 28th Edition. (Stuttgart: Deutsche Bibelgesellschaft, 2012), Mt 10:16–20. “16 Ἰδοὺ ἐγὼ ἀποστέλλω ὑμᾶς ὡς πρόβατα ἐν μέσῳ λύκων· γίνεσθε οὖν φρόνιμοι ὡς οἱ ὄφεις καὶ ἀκέραιοι ὡς αἱ περιστεραί. 17 Προσέχετε δὲ ἀπὸ τῶν ἀνθρώπων· παραδώσουσιν γὰρ ὑμᾶς εἰς συνέδρια καὶ ἐν ταῖς συναγωγαῖς αὐτῶν μαστιγώσουσιν ὑμᾶς· 18 καὶ ἐπὶ ἡγεμόνας δὲ καὶ βασιλεῖς ἀχθήσεσθε ἕνεκεν ἐμοῦ εἰς μαρτύριον αὐτοῖς καὶ τοῖς ἔθνεσιν. 19 ὅταν δὲ παραδῶσιν ὑμᾶς, μὴ μεριμνήσητε πῶς ἢ τί λαλήσητε· δοθήσεται γὰρ ὑμῖν ἐν ἐκείνῃ τῇ ὥρᾳ τί λαλήσητε· 20 οὐ γὰρ ὑμεῖς ἐστε οἱ λαλοῦντες ἀλλὰ τὸ πνεῦμα τοῦ πατρὸς ὑμῶν τὸ λαλοῦν ἐν ὑμῖν.”