(Before I start... there are a lot of links in this post. They are links to Scriptures. I encourage you to click them and read the original verses. Those verses will back up what you're reading, and help you to understand and digest the post. I'm not making this stuff up! It's in the Bible!)
I'm convinced that God expresses Himself constantly through visual aids. He paints pictures in His creation. I don't think that God used the word "father" to describe His relationship to His children because God looked down and saw someone with their father and said, that's what I'm like! I think that God is the original, and earthly fathers were created by God as a picture of His relationship to us. In fact, God even called the Israelite nation His "firstborn son" and delivered them physically from slavery in Egypt, in anticipation of His "only [one-of-a-kind] Son" Who would not be delivered, but Who would be the deliverer, bringing God's people out from spiritual slavery to sin.
Israel, as the "firstborn son," was God's "physical" people. They were delivered from physical slavery in Egypt. So "son" described God's relationship to His physical people, who are the children of Abraham by their bloodline. But God has always wanted something more. Over and over, especially in the prophets, we find God describing, almost wistfully, a time when they would be "His people" and He would be "their God". Here, for example. And here, and here, and here, and here, and here. Even when they messed up, God still wanted that intimacy with them.
The Church, on the other hand, has a relationship with God like that between a husband and wife. This is God's spiritual people, who are the children of Abraham via their faith. God wanted the Israelite nation to be His spiritual people as well, and when they messed up and worshiped idols, He even went so far as to call them a "faithless bride" (see Ezekiel 16 for a vivid picture of this), quite regularly referring to their attraction to idols as prostitution. God was seeking a bride who would approach Him by faith; a husband and wife desire to please each other, but without faith, we cannot please God. If we try to approach God without faith, we will wind up turning away from Him, prostituting ourselves to some idol or another. God wants us to draw near to Him, to submit to Him much as a wife is to submit to her husband. God wants us close!
How vivid is the image that when Christ looks on the Church, his emotional response is the same as the response a man has when he looks at his bride on their wedding day? That new husband loves, he wants and desires. He wishes to be close to his wife, to possess her, to never be away from her! And that is the way God feels about us. God's desire is not for a slave, a vassal, an underling... God's desire is for a companion. A lover. Our relationship with God has many facets... He is our Father, He is our King, we are His servants, we are His children. But at the end of this world, in the book of Revelation, the Church is not described in any of these ways, but as Christ's bride. And God's heart desire is once more spoken: "And I heard a loud voice from the throne saying, 'Behold, the dwelling place of God is with man. He will dwell with them, and they will be his people, and God himself will be with them as their God.' " (Revelation 21:3 ESV)
Very possessive language.
Are you the possession of God today?
Is He yours?
(A previous post with some related thoughts is right here.)