Someone asks you to help, and three better candidates spring to mind. You can supply their names before the question is finished. Moses had an answer ready for his assignment, too. Several answers, actually.
"Who am I?" "What if they ask Your name?" "What if they do not believe me?" "I am slow of speech." Then the honest one: "Please send someone else" (4:13). Watch how God answered the first question. Moses asked, "Who am I?" God answered, "I will be with you" (3:12).
God answered a question about Moses with a promise about Himself. His presence was the qualification, and He makes you the same promise. Insecurity stares at itself and stays put. Humility looks at God and goes.
A calling includes the One who sends
Moses' questions arise inside a specific account of God acting for an enslaved people. Read God's concern in Exodus 3 before focusing on Moses' reluctance. The mission begins with God's attention to suffering.
God's promise of presence doesn't mean Moses suddenly gains every skill or stops asking questions. The narrative includes further conversation and provision. Courage can grow while a person still needs preparation and help.
Examine the request in front of you rather than assuming every invitation is God's assignment. Does it fit your responsibilities, gifts, and capacity? Wise counsel may confirm a yes or clarify a no. Humility can receive help and make an honest decision without pretending to be fearless.
Consider the actual invitation
What responsibility is yours here? What preparation or help would you need? Answer those questions before either accepting from pressure or declining from fear.
A question to sit with
Where am I using a question about my worth to avoid a clear, manageable responsibility?
You can take this slowly.