Jethro, the father-in-law of Moses, was not an Israelite. In fact he was a pagan priest, and so we might not expect him to be portrayed very positively. But the opposite is the case; in this chapter he gives some wise advice about delegation, which Moses accepts (vv.13-26), and more importantly he listens to all that Moses tells him about the Exodus experience so far (v.8).

And then he responds:

He 'was delighted to hear about all the good things the LORD had done' (v.9)
He exclaimed, 'Praise be to the LORD, who rescued you' (v.10)
He said, 'Now I know that the LORD is greater than all other gods' (v.11). This is particularly remarkable, because as we have already seen, it took a long time for both the Egyptians and the Israelites to come to 'know' that the LORD is God - but Jethro seems to have got there in an instant.
He made a sacrifice to God (v.12)

The Holy Spirit is not mentioned, but clearly someone was at work in Jethro's heart. It all started in v.8, when Moses gave an account of what God had done for him and his people. He did not pretend that things were easy, but he brought God and his salvation into the conversation:

Moses told his father-in-law about everything the LORD had done ... for Israel's sake and about all the hardships they had met along the way and how the LORD had saved them.

What a model this is for how God can use his people to impact those around us with the good news of God's salvation. How can we follow Moses' example in our encounters this Christmas with people who do not yet worship the Lord?