The credibility of God's existence does not really depend on whether we can see Him or not but will depend on the extent to which He must and does affect and cause everything else. We believe that the sun is in the sky at midday in summer not because we can clearly see the sun (in fact, we cannot) but because we can see everything else. While it is very hard to comprehend God, it is much more important and less difficult to realize that everything requires a first cause. We know God exists because we see everything else.