While it is true that God all the more greatly esteems faith and belief over firsthand knowledge, all such faith and belief is founded upon the firsthand witness testimony of actual knowledge and personal interaction with God. A real God interacting with real people. Since the beginning, when Adam "walked with God"...he did not "believe" there is a God, he knew, and throughout all of human history God has done likewise with every generation.
Every generation has people who have attested to this fact, from which we have the scriptures (the bible), and the word of Christ throughout the church age by His promise of the Holy Spirit, including many personal encounters. Since the apostle Paul, many have been "caught up in the spirit", of which I can personally attest, is true.
Your faith and belief is not in vain.