Doubting shows up in many ways: asking but not waiting for the answer; asking only once or for a short time and giving up; not even bothering to ask.
Doubting can show up as either despairing of ourselves (I’m not worth it; I don’t have what it takes; I’m a loser; why does this always/only happen to me? I just have to figure this out myself; etc.) or disparaging God (He doesn’t care; He won’t do anything one way or the other; He can’t help; God is ruining my life…).
James tells us:
"If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him. But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind. That man should not think he will receive anything from the Lord; he is a double-minded man, unstable in all he does." (James 1:5-8 NIV)
Doubting leads to being double-minded and unstable, influenced more by random external forces.
Think of folks who only do things depending on how they feel that day, check horoscopes, look for superstitious signs. Like the ocean waves, whitecaps with blowing spray – contrasted against a mirror lake at morning, surface of the water like glass reflecting the beauty of heaven. "Be still and know…" (Psalm 46:10)
Call your doubting what it is and come to God in faith knowing that He gives generously to all without finding fault.