The second argument actually has puzzled me more. That is to notice that we can reasonably disbelieve. Nothing in life would be unexplainable. The question then is why wouldn't God be obvious? The answer is that God chose to have us respond to him by faith. If he made Himself obvious like the sun or the ocean we could not believe in him by faith. We would have overwhelming physical evidence that would force us to believe. That is not faith. But why faith? Why does God make having a relationship with Him so hard? Especially when one consequence of that difficulty is that many people will end up in hell.
The answer lies in the same place. In free will and the dignity of man. The kind of change God wants to make in us is so profound and so deep that God refuses to force us. But He has made us rational beings. One way rational beings can be forced is through irresistible arguments or undeniable evidence. So he has made all the arguments resistible and all the evidence deniable. But at the same time, with the eyes of faith, the arguments must irresistible and the evidence undeniable. I mean people of faith are asked to surrender everything from private opinions to intimate relationships to material wealth even including their very lives. God can't ask rational beings to do that with no evidence or argument.So God needs something that one man will find compelling enough to reorder his entire life and the next man will have no trouble dismissing it entirely. This is what faith is.
What is more, people of faith need to be transformed into saints. Millions of people having their lives completely transformed by the power of God's grace. Yet people who don't want to notice should be easily able to ignore this fact. If it wasn't our reality we might think it impossible.
Look at John 16:7,8:
But I tell you the truth: It is for your good that I am going away. Unless I go away, the Counselor will not come to you; but if I go, I will send him to you. When he comes, he will convict the world of guiltWhen Jesus goes away He removes the most power evidence of the resurrection. That is His live body walking around, eating, speaking, etc. This would be undeniable evidence. Somehow the Holy Spirit cannot operate until the undeniable evidence is removed. He works by faith. Faith only kicks in when sight fails. Faith allows us to come to God without losing our dignity as human beings. We can freely say "My Lord and my God" as St Thomas did in Jn 20:28. We are not being compelled. We are falling in love. God would not have it any other way.