'Wavers' in the Bible

‘Now if your fellow countryman becomes poor and his hand falters with you [that is, he has trouble repaying you for something], then you are to help and sustain him, [with courtesy and consideration] like [you would] a stranger or a temporary resident [without property], so that he may live among you.

But he must ask [for wisdom] in faith, without doubting [God’s willingness to help], for the one who doubts is like a billowing surge of the sea that is blown about and tossed by the wind.