Hagar had NO SAY, she was a slave. She only complained to God, NEVER to Abram or Sarai.... And you are right at this stage they were BOTH sinners, but Abram would have a name change, and so Sarai, and with the name-change a spiritual change as well... Ths you should NOT MISS... It did not matter how big or small they sinned, God was going to change that. FOR ABRAM AND SARAI... not for HAGAR OR ISHMAEL....
Abram would get the boy Isaac, and God would make Abraham a righteous man by the FAITH God would implant in Abraham... And God did! God says in Romans 4 that teh faith was reckoned to Abraham for righteousness... So I have NO problem that Abram and Abraham, were God's work to make Abram the sinner, Abraham the righteous. I will not take God on in an argument about this fact. It is also more evident of God making Saul the sinner, Paul the Apostle...
ALL these things is God's Word in ACTION. This boy ISAAC was the first boy an ANGEL (EVEN GD HIMSELF) predicted (prophecied) to be born. Also HIS NAME WAS GIVEN TO THE PARENTS BEFORE HE WAS EVEN BORN.... WOW!
Well let us have another WOW.... Then MANY YEARS LATER... this time an angel appeared to Sacharias and this is ALSO an old couple with no kids... Same as Sarai and Abram, but these two were ALREADY BLAMELESS and they BOTH were RIGHTEOUS BEFORE GOD... WOW!!!! Imagine two people, a couple that GOD HIMSELF DECLARES RIGHTEOUS BEFORE HIM.... WOW!!!! Now we do not know when this old man prayed to God for a son, but he did.... MAybe every day, we do not know this... All we know is God heard the prayer and God decided to give this old man the son he wanted....Then the Angel said to the old man.... You shall have child, and you shall call him JOHN.... WOW!!! Another name before the Child is born.... This time the angel said.... HE SHALL BE GREAT IN THE SIGHT OF THE LORD.... Why? He SHALL BE FILED WITH THE HOLY GHOST EVEN FROM HIS MOTHER'S Womb...... And unlike ANY OTHER MAN EVER BORN SAVE ONE... This is the ONLY MAN EVER (save ONE) that will be filled with the Holy Spirit from day 1.
Then another woman is preagnated, but as a VIRGIN... Mary, and both she and her husband is told that this is the CHRIST... Also HIS name was given before he was born.... WOW three special boys this? Is it not? And Isaac was special, but John more so and Jesus? WOW! Thank you for this chat... IT is God at WORK...