All day long He has stretched out His hand to a gainsaying people. Why? They kept rejected the message. Why would God, in His longsuffering, reach out His hand to such a people if He has predestined them not to believe the message?
Your quote is from Romans 10:21. The disobedient and gainsaying people that he is talking about is Jacob/Israel, his elect, who does believe, but do not have the full knowledge of the gospel, because they are still babes in Christ, and do not understand the doctrine of Jesus. Isaiah 28:9-10, Whom shall he teach knowledge? And whom shall he make to understand doctrine? Them that are weaned from the milk, and drawn from the breast. For precept must be upon precept, precept upon precept, line upon line, line upon line, here a little, and there a little.
Romans 10:1-3, Brethren, my heart's desire and prayer to God "for Israel" is, that they might be saved (delivered=Greek interpretation). For I bear them record that they have a "zeal" (evidence that they are born again) of God, but not according to knowledge. For they being ignorant of God's righteousness (that is revealed in the doctrine), and are going about to establish their own righteousness, have not submitted themselves unto the righteousness of God.
Gen 33:28, And he said, Thy name shall be no more called Jacob, but Israel; for as a prince, thou has power with God, and with men, and has prevailed. Romans 9:11, For the children being not yet born, neither having done any good or evil, that the purpose of God according to election might stand, not of works, but of him who calleth, it was said unto her, the elder shall serve the younger, As it is written, Jacob have I loved, and Esau have I hated.
Jacob/Israel is representative of God's elect, the church. Because newborn babes in Christ are without knowledge, and are "disobedient and gainsaying" and are in need to be taught the doctrine is why Jesus instructed his Apostles to go and preach to the lost sheep of the house of Jacob/Israel, Matt 10:6.