Faith and trust have similar meanings, and often people will use the words interchangeably. Even Merriam-Webster defines faith as “belief and trust in and loyalty to God.” For most people there is no practical difference between faith and trust; to them, the two are synonymous. Any differences that exist are very fine.
One difference is simply grammatical. Trust can be either a noun or a verb, depending on context. As a noun, trust means “assured reliance on the character, ability, strength, or truth of someone or something”; as a verb, it means “to rely on the truthfulness or accuracy of,” “to believe,” “to commit or place in one’s care,” or “to place confidence.” Faith is always a noun (except in cases of its archaic use as a verb).
In Scripture, faith is defined as “the substance of things hoped for, the evidence of things not seen” (Hebrews 11:1). In other words, faith involves trusting in something you cannot explicitly prove. Faith is inseparable from trust; it’s the confidence that God can and will do what He says in His Word. Faith includes both intellectual assent to something and trust in it. So we believe something to be true, and we also place our trust in it—we rely on it. Faith recognizes that a chair is designed to support the person who sits on it, and trust demonstrates the faith by actually sitting in the chair.
Faith without trust is not faith. Belief without reliance is empty. Many people believe certain facts about Jesus Christ, but knowing those facts to be true is not what the Bible means by “faith.” The biblical definition of faith requires trust in—a commitment to—the facts.
An example of the relationship between faith and trust is a trust-fall. You have faith that your friends will catch you even though your back is turned to them. You believe they will not let you hit the ground. The act of falling—as the name of the exercise implies—is trust. You demonstrate the faith you have in your friends. Trust in God is a core aspect of biblical faith.