Isaiah 59:21

As for Me, this is My covenant with them, says the Lord: My Spirit which is upon you (writing the Law of God on the heart), and My words which I have put in your mouth shall not depart from your mouth, nor from the mouths of your (true spiritual) children, nor from the mouth of your children’s children, says the Lord, from now and forever.

God will speak to His people through the generations of His children here on earth. God will continue to instruct and inspire until the day Jesus returns. God will not leave us without understanding of His promises, and the Word will not be lost down the generations. He will always be there, providing wisdom and comfort.