God had promised Abraham to make him a great nation (Genesis 15). God had even made a covenant with Abraham, showing him that His promises were sure. Now, however, Abraham and Sarai had grown old and they still had no son.
In this situation, Sarai had an idea:
So Sarai said to Abram, “See now, the Lord has restrained me from bearing children. Please, go in to my maid; perhaps I shall [a]obtain children by her.” And Abram heeded the voice of Sarai.
Thus, Sarai was stating a fact; she could not have children until then. So what is the problem with this statement? It happened in unbelief, without trust in God's word! Abraham was probably also not so strong in faith at that moment, so he went along with the idea. We don't know what he was thinking. Maybe he said to himself that God would fulfill his promise just in this way. And at first it seemed to work out, but very soon the problems came.
This incident is also of great significance for us believers today. We have received many promises from God. He will build His church, transform us and make His house glorious. Moreover, our heavenly Father takes care of all practical concerns in our lives. However, we also often worry and look for our own solutions when God does not act when we want Him to. Maybe you look at yourself and think, "God will never make it with me! I have always been like this and will always be like this. It may be a fact that you had no patience in the past or the like, but didn't God promise to transform us? Our faith is based on God's word, not on the circumstances of the moment. Don't try to find your own solutions, God's way is the best. Even if our own ways look promising at first, they will bring us problems.
Two Covenants - Hagar and Sarai
In Galatians 4:21-31, Paul looks at the story of Abraham again from a different perspective. Hagar as an image of the law and Sarai as an image of faith. The law makes demands on man, which he must keep by his own efforts. Faith, however, makes free and through our faith we become heirs of the promise.
Now we, brethren, as Isaac was, are children of promise.
We live by faith and are children of promise. Let us be patient and just trust in God. His time and guidance are best.