As humans we believe only what we can see but God explains what He wants:
Heb 11:1
1 Now faith is being sure of what we hope for and certain of what we do not see.
NIV
So God is expecting us to believe what we cannot see. Hmm that’s very different from what we as humans believe. And many of us believe only what we can see.

How many people have ever seen God the Father? None.

Is God the Father real? Yes He is.

How many people have ever seen God the Holy Spirit? None.

Is God the Holy Spirit real? Yes.

It sounds like we, humans should adjust our belief system to faith and not sight.