λόγος — logos
Frequently used of God, through his messengers: a word, spoken or written.
In many times and in various ways, God spoke to man through his prophets. He didn’t fall silent after the Fall, he knows we are forgetful creatures. Throughout the years, he spoke to men who delivered his message of judgement, repentance, and mercy. As he did so, he included nugget after nugget of prophecy about the Saviour he had promised.
Only he could have truly known about it at the time but his word is truth and he gave it to remind is that he, the God who cannot lie, had promised to reconcile us to himself.
All would become clear in time.