(one's) passport to (something) phrase
That which enables one to achieve, discover or get access to something good or worth having or doing.
This certificate is my passport to a decent job.
This phone is the police's passport to solving the crime.
A softly mellifluous voice is her passport to a professional singing career.
A resource that will allow the possessor to access to power, knowledge or understanding
The origin of this phrase is not clear.
Daughter: So I really want all my friends to have a great time. I was thinking it would be a good idea to have some candy out on the tables for people to snack on.
Mother: Well, if you want them to really enjoy themselves, candy is dandy but liquor is quicker.