I will accept physical evidence I can see, touch, and examine in public. Nothing less.
All we have are alleged witness accounts, claims of alien bodies, claims of alien spacecraft wreckage, claims of alien reverse engineering, claims of alien technology, claims of alien implants, claims of alien hybrid babies, blurry photos, and short and shaky videos people tell me, without evidence, are alien spacecraft.
Show me physical proof I can see, touch, and examine and I will accept aliens are real and have visited Earth.
Some believe in Jesus, sight unseen, all through witnesses long since dead. How is this different?