For this is how God loved the world: He gave his one and only Son, so that everyone who believes in him will not perish but have eternal life. (John 3.16 NLT)

Faith does not make sense to those who do not yet have it. How can we believe and love someone whom we have never met? But that is indeed the first step that is needed: to trust although we "do not see".

And once we truly trust Jesus, we experience "inexpressible joy" as a result. (Not all laughter and sunshine kind of joy, but "inexpressible joy".)

This, for those who trust, is enough evidence to keep on believing Jesus.

You love him even though you have never seen him. Though you do not see him now, you trust him; and you rejoice with a glorious, inexpressible joy. The reward for trusting him will be the salvation of your souls. (1 Peter 1.8-9 NLT)