Genesis 21 contains three very different stories. One of the three is clearly significant if we are familiar with the larger story, but the others seem relatively unconnected. And yet – like many of the stories in Genesis, they find a place when we remember that the central character is God and not Abraham or anyone else. This chapter and these stories – like the chapters and stories nearby – reveal God to us. They demonstrate His faithfulness as well as His compassion. They do so in order to call us to trust Him and live lives that demonstrate that trust.
The chapter begins with the long-awaited birth of Isaac (21:1-7). Just as He repeatedly promised (15:4; 17:21; 18:10), God miraculously granted Abraham and Sarah a child in their old age. Many years had passed, but God had not forgotten what He promised. Even though it may have seemed like He had changed His mind, He was simply waiting for His appointed time. Without a doubt, this is a clear demonstration of the character of God. It is a reminder that nothing is impossible for God (Matt. 19:36). Even if something seems completely improbably to us, it is never so to God. This does not mean we will have whatever we want, but it does mean we will have whatever God wants – regardless of how incredible or impossible it may seem.
At the same time, the birth of Isaac shows us the faithfulness of God. He always does what He says He will do. He had promised Abraham a son, and He delivered on that promise – just like He always does. If God declares it, it will be so, and there is no good reason for us not to believe Him. We see this in the final part of the chapter as well in the treaty made between Abraham and Abimelech (21:22-34). Just as God promised (12:2), He blessed Abraham by granting him peace and favor with the local ruler. God promised that His favor would be upon Abraham, and it was so. Again, this is a reminder for us, because the character of God has not changed. He still does everything He says He will do. His word is full of promises, and we should not read them as mere possibilities or wishes or hopes or desires. God is not like us, because He actually can do whatever He pleases. So if He promises, we can trust – and we should. Read His word, feed on the promises, and rest.
This chapter also clearly demonstrates the compassion of God. In the middle of the chapter is an odd story about Hagar’s son, Ishmael, laughing at Isaac and both he and his mother being ejected from the house (21:8-21). Even though Abraham is saddened by the turn of events, God comforts him by promising to care for the child. Then, when it seemed as if the child would die for lack of resources, God provided. In Hagar and Ishmael’s time of greatest need, God answered. He is compassionate – even with those who are not part of His chosen people. As the Bible makes clear repeatedly, He pours out His goodness on both the just and the unjust (Acts 14:17; 17:25). This is good news, because we do not deserve His kindness. It also means we should show that same kindness to others – as those who have received it ourselves (Matt. 5:43-48). God is compassionate.
What does this mean then? We should trust God and rely on Him to provide for us and care for us. If He is strong (able to do whatever He pleases) and faithful (committed to doing whatever He says) and compassionate (willing to do good even when it is undeserved), then should we not submit to Him and trust Him and rely on Him? Instead of trusting ourselves, we should depend entirely on Him and His promises and His provision. In fact, Paul uses the episode with Hagar to make this very point in Gal. 4:21-31). Hagar and Ishmael represented Abraham’s attempts to bring about the blessings of God through his own strength. He needed to “cast out” the slave woman and rest entirely on his trust in God. In the same way, we need to seek out the ways in which we are trusting ourselves and our own strength and “cast them out”. We are children of promise and not children of the flesh – which means we trust God and not ourselves. God is strong and faithful and compassionate, so we should depend on Him rather than anyone else.