Most people would not (choose) to spend their time with people they don't trust whether it's a romantic relationship or otherwise!
Nevertheless trust like respect is something that should be earned overtime. In order to be trusted one must be trustworthy!
In order to be trustworthy one must demonstrate (honesty and integrity). Trusting someone does not mean you "can't ask them questions". Trusting someone means you believe they will give you "honest answers" to your questions!
There are many people who state they'll "trust anyone" until they (prove) themselves to be untrustworthy. This is a (conman's) dream! There is no virtue in being a gullible fool. Always use good commonsense and allow time for relationships to build on a solid foundation. Honesty leads to trust. Trust leads to loyalty.