Fantastic Four #66, written by Stan Lee and pencilled by Jack Kirby, was released in September, 1967 and featured the first appearance of Adam Warlock. At the time, he was an Enclave creation known as Him. Here’s Marvel’s synopsis of the issue:
“Learning that Alicia has gone missing, the Fantastic Four begin trying to learn what happened to her. While Alicia has been brought to the Beehive, a secret science laboratory where the scientists (dubbed the Enclave) have created an artificial being known only as “Him”, which they cannot even look at due to it’s blinding radiance. They ask for Alicia’s aid, as her delicate hand for detail and her blindness would allow her to describe to them what their creation looks like. While back in New York, Reed has created a device that recreates the scene in Alicia’s apartment just before her disappearance. Back at the Beehive, Alicia is prepared to enter the room where Him is kept, and as she confronts Him back in New York Reed has found a way for them to find Alicia: With a picture of the bracelet that her kidnapper was wearing, Reed believes that he can duplicate it.”
And here are a few excerpts I found:
Glad to see Adam Warlock hasn’t changed too much over the years. He’s always had a sort of Dr. Manhattan-esque objectivist thing going on and I’ll be damned if he doesn’t always emerge from a cocoon.