"בָּרוּךְ הַגֶּבֶר אֲשֶׁר יִבְטַח בַּי-ה-וָ-ה וְהָיָה יְ-ה-וָ-ה מִבְטַחוֹ."
“Blessed is the one who trusts in Hashem, whose confidence is in Him."
If you trust in him, then He will show you that He can be trusted. If you are בוטח he will validate your trust and be מבטחו.
Also, you are blessed if you trust not only in if you trust that Hashem will help you but והיה ה' מבטחו, you are not focused on the natural means through which he will help you but on him alone. והיה ה' מבטחו. [See Malbim]
