It is common to read these verses as being about where we go when we die, and about how to get there. Certainly Jesus’ words do promise an eternal home with God. But the focus of the passage is not on where we are going, but on our ongoing relationship with God.
Jesus speaks a number of times in this and the following chapters about “abiding.” We abide in Him, and He abides in us. The word translated “rooms” or “dwelling places” in verse 2 (“mansions” in the KJV, which at the time the KJV was written simply meant “dwelling places”) is the noun form of the verb translated “abide.”
So we are assured that even though Jesus is no longer present here on earth in the same way he was at the time he spoke these words, there is always a place for us with God, so long as we trust in Him and make a place for Him in our lives.
Jesus teaches his disciples both how not to pray – like the hypocrites or like the pagans (Gentiles) – and how to pray. The hypocrites are focused on themselves and other people’s opinion of them, rather than on God. The pagans are focused on a deity, but whatever god or gods they pray to are not ones in whom they can trust to answer their prayers.
Jesus’ followers know they have a Father who is both sovereign over all and loving toward His people. He both can and wants to meet their needs, so they can pray simply and in confidence to Him.