John 5:24
Very truly I tell you, whoever hears my word and believes him who sent me has eternal life and will not be judged but has crossed over from death to life
John 6:40
For my Father’s will is that everyone who looks to the Son and believes in him shall have eternal life, and I will raise them up at the last day
John 6:47
Very truly I tell you, the one who believes has eternal life.
I could list several more verses that make it clear: BELIEVE to have eternal life. Jesus says this several times throughout the Gospel with no mention of baptism.