1 Peter 1:8-9 (NIV)
Though you have not seen him, you love him; and even though you do not see him now, you believe in him and are filled with an inexpressible and glorious joy, for you are receiving the goal of your faith, the salvation of your souls.
I haven't seen Him either. The bible speaks of the Spirit of God as a wind which you cannot see but you can see its effect. Think about this though, Peter had seen him, touched him, lived with him. Jesus washed his feet. Peter had good reason to love Jesus. Jesus was wonderful when he walked on this earth. But look how Peter describes our joy: "inexpressible and glorious." Why? This joy does not come from within us; it is put into us; we are "filled" with it as Peter said. The Spirit himself testifies with our spirit that we are God's children. [Romans 8:16]
John 20:29b (NKJV)
Blessed are those who have not seen and yet have believed.