Last week we saw the Lord protecting the integrity of the covenant by protecting Sarah from King Abimelech. (Remember how he had taken her to be one of his wives when she and Abraham entered his territory.)
This week we’re going to see the Lord protect the covenant again by making sure there’s no threat to Isaac being the sole recipient of his father Abraham’s estate and family lineage. Because remember, even though Isaac was the chosen one, Ishmael his half brother was still on the scene and by societal law he would have had access to Abraham’s estate even though he was the son of Abraham’s hand maid not Abraham’s wife.
Sao as we go through this passage we’ll once again see the faithfulness of God loud and clear as He fulfills His promise to Abraham and Sarah by giving them their son Isaac.
Now our response to the faithfulness of God should be faith in Him. Total and complete trust in the One who’s been so trustable. He so faithfully provided a Savior through the line of Abraham and we ought to respond to Him with faith.
That means that we don’t trust in our own works to establish a relationship with Him. That means we don’t try to earn our salvation with our good deeds and our morality. We realize that the faithful God asks us to trust Him for salvation. Him alone who so faithfully will deliver.
And this is something that’s spelled out in verse after verse after verse throughout the Bible. “For God so loved the world that He gave His only begotten Son that whosoever believes in Him shall not perish but will have eternal life.” (John 3:16)
So if Scripture is so explicit about the means of salvation being faith, how come so many ‘Christian’ folks get caught up in a works-type salvation? How come so many people feel like they need to fulfill the Law, (10 commandments), for salvation?
Well, many people don’t quite understand the purpose of the Law of God and how it relates to having faith in God. The Law could never and should never take the place of faith in a person’s life. The Law of God does two main things in a person’s life:
1. The Law of God shows us God’s standards and principles for life.
2. The Law of God shows us our sin, (not achieving those standards).
The Law isn’t a means of salvation – it shows us the need for salvation. And that’s where
the faithfulness of God comes in. “But God demonstrated His own love for us, in that while we were yet sinners, Christ died for us.” (Romans 5:8) When we put our faith in the Lord for what He’s done for us, then we’re saved. We are saved by faith.
But even though it’s clear how salvation is obtained, there are many that believe in upholding the Law of God either for salvation or to maintain.
[Catholics, Seventh Day Adventists, Church of Christ, Arminians, Baptists examples.]
If they would just go back and look at Genesis chapter 21 and reference it with Galatians chapter 4, they’d see how faith in God alone is the way of salvation. Works are not the way! So let’s look at the two sons of Abraham and see this great doctrine brought out.
I. Isaac – the welcomed son
[Read Genesis 21:1-8.]
Amazing! It finally happened! The Lord was faithful to His promise and brought forth a son through the union of Abraham and Sarah in such a way that it could only have been God that did this. This was no trick, this was no fluke, this was no accident, God made the barren womb fruitful and brought forth Isaac. Look at some of the key words in the first two verses.
Abraham responded in faith to the faithful One. Sarah also responded in faith as well.
Sarah’s laughter of doubt from when she first heard the Lord say she would have a child has now turned into laughter of joy. Laughter of joy is such a wonderful thing. When something so astonishing happens that you laugh with joy is a great thing.
[Birth of my kids example.]
Sarah’s laughter has turned from doubt to joy. But that wouldn’t be the only laughter to be heard in Abraham’s household. Abraham’s son Ishmael laughed or scoffed at the celebration of Isaac’s weaning.
The word used for “mocking” is the same root word used for Isaac’s name. So it seems that Ishmael is using Isaac’s name in a way that mocks who he was. Now why would this 16 or 17 year old do something like that at his brother’s celebration?