The LORD said, “I will surely return to you about this time next year, and Sarah your wife shall have a son.” And Sarah was listening at the tent door behind him. Now Abraham and Sarah were old, advanced in years. The way of women had ceased to be with Sarah. So Sarah laughed to herself, saying, “After I am worn out, and my lord is old, shall I have pleasure?” The LORD said to Abraham, “Why did Sarah laugh and say, ‘Shall I indeed bear a child, now that I am old?’ Is anything too hard for the LORD? At the appointed time I will return to you, about this time next year, and Sarah shall have a son.” (Genesis 18:10-14 ESV)

He did not weaken in faith when he considered his own body, which was as good as dead (since he was about a hundred years old), or when he considered the deadness of Sarah’s womb. No unbelief made him waver concerning the promise of God, but he grew strong in his faith as he gave glory to God, fully convinced that God was able to do what he had promised. (Romans 4:19-21 ESV)

For it is written that Abraham had two sons, one by a slave woman and one by a free woman. But the son of the slave was born according to the flesh, while the son of the free woman was born through promise…. So brothers, we are not children of the slave, but of the free woman. (Galatians 4:22-23,31 ESV)

        Against all odds the child of promise, Isaac, was born to Abraham and Sarah. The Scriptures make it clear that Sarah’s pregnancy was not a medical anomaly, but a miracle. Sarah had long ceased being “in the way of women”. In fact, it was so long since then that there was no natural hope of child bearing. Therefore, when God kept his promises he got all of the credit. It was the working of God alone which brought this baby about. This miracle was such that Paul even refers to the child of promise as being born “according to the Spirit”.

The way Isaac was born, through the promise and by the Spirit, is exactly the same way that every child of promise is born. We see in Isaac’s generation a picture of the way God works in bringing into life every child of promise. There is only deadness and hopelessness in our sin, but the sure decrees of God, his promises, through the agency of the Spirit bring about the impossible, the birth of children of promise by faith in Jesus Christ.

In John 6:63, Jesus said, “It is the Spirit who gives life; the flesh is no help at all.” In the flesh, in a way reasonable to man, Abraham and Sarah at first attempted to do what only the Spirit can do – Abraham took a bond woman, Hagar, as a wife and had a son with her, Ishmael. They did not believe in the immutability of God’s promises and the power of his working, but allowed their mind to follow the patterns of the world – going after what made sense to them. They felt that because God had not kept his promise yet that perhaps it was because they needed to do their part. They allowed themselves to be duped by a theology of cooperation rather than of trust.

We also need to realize that if we are children of promise, the offspring of Abraham by faith, we were born out of deadness exclusively as a result of the unchanging promises of God being worked out by the power of the Spirit. God declared that you would be born into the family of freedom and it was so. “It is the Spirit who gives life, the flesh is no help at all.” Abraham and Sarah found this to be true after the incident with Hagar. The promise of God was sufficient. The deadness of Sarah’s womb highlighted the necessity of a miracle, not 90% plus 10% man, but 100% the working of God – doing the impossible through human vessels.

As a pastor I can’t help but see how this connects to the way we do ministry. So often we see the promises of God and we claim to believe them, but we want a shortcut. Nothing seems to be happening so rather than trusting and pursuing faithful rest, we find a Hagar, whether it be some pragmatic construct, method, or adaptation of God’s message. We scheme, in a well-meaning fashion, to help God fulfill his promises. We assume because nothing has happened yet, because no children have “been born” that maybe we understood the promise wrong, maybe our methods need tweaking. As a result of this well-intentioned tampering we may see results in our ministry, we may seem to have success and feel that God is indeed working, but the fruit of our effort is actually a bunch of Ishmael’s running around – the results of us using our own means to reach God’s promised end.

God is calling us in ministry to simple trust. To speak of that which we have seen and heard in the Gospel. God brings children of promise into being through the means of his Word being spoken. We are to proclaim it. Clearly and consistently. That may seem weak. Foolish. Like the thought of two elderly people having a baby. But this is what he has called us to. The years may roll and we may see little results, if any, yet we must not resort to using a Hagar, but must trust in God’s promise and power, knowing that from the deadness of Sarah’s womb, God brings forth children of promise.