1) "God holds the key to all unknown, and I am glad. If someone else should have the key, or if he trusted it to me, I might be sad."
... for which read, "it would be a complete cosmic disaster."
2) (Sorry, Dave Heddle) "You ask me how I know he lives, he lives within my heart." That way lies existentialism - Christ doesn't only live because I "feel" that he lives "deep down inside". How did the disciples know that he (Jesus) lived? Well, Jesus met them, so that could have been enough. Instead, however, when he spoke to them, he focused on the fact that the Scriptures said that he would suffer and die, and enter into his glory. (Luke 24:27,44) Why? Because future Christians would not meet the risen Christ. So how are they (we) to know? Because the Scriptures say so.
So, you ask me how I know he lives? Because it was necessary that the Christ should suffer these things and enter into his glory - and because the gospels record that was what happened to Jesus.