The second verse of Hebrews chapter 3 continues the comparison between Moses and Jesus. It says that Jesus “was faithful to him who appointed him, just as Moses also was faithful in all God’s house.” This is God’s testimony regarding Moses’ faithfulness not just the author of the Book of Hebrews. Back in the book of Numbers (12:7) when Aaron and Miriam challenged Moses’ authority, God speaks and says that in the past He spoke to prophets through dreams and visions, “But this is not true of my servant Moses; he is faithful in all my house.” It’s obvious that the writer of Hebrews is quoting from Numbers. Moses’ faithfulness is with respect to God’s house or household. This refers to the people of God. Moses did God’s bidding, although reluctantly, in leading God’s people out of slavery in Egypt. But Jesus had a more honorable role with respect to God’s people.
Hebrews 3:3 explains this. Putting verses 2 and 3 together, it says Jesus “was faithful to him who appointed him, just as Moses also was faithful in all God’s house. For Jesus has been counted worthy of more glory than Moses—as much more glory as the builder of a house has more honor than the house itself.” If “God’s house” is referring to God’s household as I believe it does, then it’s right to say “in” God’s house includes the fact that Moses was part of God’s household. God chose him to a specific task within God’s people and God stood up for Moses when he was challenged by others with respect to that calling.
The writer of Hebrews leans on what he had already said in Hebrews 1:2. God used to send his “Word” to his household through His prophets, of which Moses was one, “but in these last days he has spoken to us by his Son, whom he appointed the heir of all things, through whom also he created the world.” Moses was faithful to His calling and deserves recognition. But Jesus was the caller. Jesus was the builder of the house of which Moses was just a part of. Whereas Moses spoke words from God to God’s people, Jesus is the “Word” of God Himself. Moses was a messenger. Jesus was both the messenger and the message! Choose the builder!