war' between the Seed of the Woman and Satan's 'seed' had well begun at this time and Satan was attacking that Seed of the 'eth' Ha'adham' (Gen.3:15).
     Because of this terrible state of affairs upon the earth at that time, GOD was 'grieved' that He had made man also in the flesh, for all were already made in the spiritual and had existence in the first earth age (see Gen.2:1 in the Manuscripts with "all the host of them").

Gen 6:7   And the LORD said, "I will destroy man whom I have created from the face of the earth; both man, and beast, and the creeping thing, and the fowls of the air; for it repenteth Me that I have made them."

     Since Satan was the cause of the overthrow (katabole) or rebellion against God in that time 'of old', long before this event of Noah's day, and God had to cleanse the earth then using water, the earth at the beginning of this second age of flesh had gone sour again, being polluted by Satan through his hosts of fallen angels. So naturally God didn't want to have to start this second age of flesh, putting the spirit of man into a flesh body, which made man more animalistic when sinking into evil, and this is why God 'repenteth' and was 'grieved' in His heart.
     It is important to understand this idea of God being sorry that He made man on the earth. The actions of our Father are always perfect and 'good', as in Gen.1:31. Because He is 'longsuffering' towards His children, He wiped the first earth age clean for a new start to give all a chance to 'return' back to Him. If Satan had not rebelled, no fresh start on the earth would have been needed. This shows that God will not force anyone to love Him. Each must come to Him of their own free will.

The flesh age was started in order to allow Salvation through His Only Begotten Son Jesus Christ, Immanuel ('God with us' in the Hebrew) to come to earth, to be born of woman in the flesh, then tried and crucified by the workers and seed of Satan, sealing the devil's own death sentence and those with him.

 

  Heb.4: Read All. 1 Let us therefore fear, lest, a promise being left us of entering into His rest, any of you should seem to come short of it. 12 For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.

 

Because God felt sorry in His heart that He had made man also flesh upon the earth for any other reason, and to say that God is human and not perfect, and can make mistakes. That false type of reasoning exists within some atheistic circles because they do not understand God's overall Plan of Salvation.

Furthermore, when a Church or proclaimed teacher of God's Word fails at properly teaching these verses here in Gen.6, it misrepresents Christianity to the non-believer, driving them away to man's systems of philosophy. And that's how many atheists interpret the reason why God was sorry He made man on the earth, saying that He couldn't quite get it right the first time. That false outlook is a gross error in understanding the Truth.

 

Gen 6:8 But Noah found grace in the eyes of the LORD.

Gen 9:    THESE are THE GENERATIONS OF NOAH: Noah was a just man and perfect in his generations, and Noah walked with God.

Gen 10:  And Noah begat three sons, Shem, Ham, and Japheth.

     Noah found 'grace' because he was aware of the fallen angels intermixing, so he kept his bloodline pure from 'the man Adam' and most of all, obeyed God which will always bring you God's blessings.