If God loves us and wants us to know and believe in him, why be so completely invisible? What is the purpose of being so illusive to those who believe and worship him?
This is an interesting reason for rejecting Christianity. First, it can be argued that God is not invisible. He came to earth as a man, Jesus, and revealed Himself in human form to hundreds of eye witnesses who recorded the account in Scripture. Second, anyone that has seen a glimpse of God has hardly been able to handle it. Think about Moses when he came off the mountain after meeting with God. His face shone and the people could hardly look at him. And they were only seeing the effect of God, not God Himself. We could not handle seeing the glory of God in the infinite form.
However, we do see glimpses of God all around us. Creation evidences God. Our very existence is evidence of God. The design around us indicates a Designer.
For in him we live, and move, and have our being; as certain also of your own parts have said, For we are also his offspring. Acts 17:28 KJV
So my restatement of the reason would be:
God’s glory is so great that we cannot see Him and live. In His goodness, we see evidences of Him through the creation, through the eyewitness accounts of His Son recorded in Scripture, and through our very existence. He is invisible only to those who choose not to see the evidences He has given.