When the gospel of Jesus Christ’s Blood and Body is presented, the hearer has freewill to choose to receive salvation or reject it.
Perhaps they did not, but they did exercise their free will when they refused to heed Joshua and Caleb and listened to the other ten spies sent into the promised land. When they had a golden calf made and worshiped it. When they refused to look at the serpent that Moses put upon his staff, or when they tried to gather more than a days worth of manna, or when they stuffed themselves with quail meat; even as they beheld the Lord's miracles wrought through Moses.
Paul tells us of how Pharaoh's heart was hardened by the Lord and Paul responds to this very question, by showing how the Lord bare with much long suffering regarding Pharaoh's sins, withholding judgement in order to show his power and declare his name to the world's nations of that time. (See Rom 9: 17-23)
Paul tells us of how Pharaoh's heart was hardened by the Lord and Paul responds to this very question, by showing how the Lord bare with much long suffering regarding Pharaoh's sins, withholding judgement in order to show his power and declare his name to the world's nations of that time. (See Rom 9: 17-23)
Ps 106:7-8
7 When our fathers were in Egypt,
they gave no thought to your miracles;
they did not remember your many kindnesses,
and they rebelled by the sea, the Red Sea.
8 Yet he saved them for his name's sake,
to make his mighty power known.
NIV
So, it certainly doesn't appear that God redeemed Abraham's descendants due to the awesome power of their "free, sovereign" will. God acted unilaterally. It was only AFTER God had parted the sea, they crossed over safely and the sea swallowed up the Egyptian army did they finally come to their senses and believe his promises (v.12). The crossing over on dry land between the two huge walls of water was a type of baptism, according to Paul (1Cor 10:2).