So "logos" is basically "reasoned discourse". So the above quotes are basically saying that in the beginning God was reasoned discourse as in the Old Testament. But then God became flesh through the Christian concept of Christ. This change was needed because people cannot understand reason, so a concrete "flesh" version of God is needed.
This is how I see the story. Jesus was a smart guy who realized that Judaism was off track. Jesus was charismatic enough to get his message out and get some followers. But then Jesus died. How could the followers of Jesus spread his message without Jesus's charisma? Certainly not by reason. The Old Testament had failed as could be seen by the state of Judaism at that time. Something new was needed. The solution was to make God flesh (concrete) by making Jesus devine.
No religion is based on reason. All give authority to something concrete. Judaism gives authority to the rabbis. Islam gives authority to the Quran. And Christianity gives authority to a concrete manifestation of God in Christ.