The spare key marks a practical kind of trust that speeches rarely improve.

Some kinds of trust are demonstrated rather than declared. Handing someone a key says you are willing for them to be in your home when you are not there, which no assurance can quite match. Practical trust is specific and slightly risky, and that is exactly what gives it weight.

If there is somebody you would say you trust, look for the concrete version of it you have not offered yet. A key, a password, or a task with real consequences says more than another round of telling them how much they mean to you.