Exodus 13 - 16

Moroni said -

"...I would show unto the world that faith is things which are hoped for and not seen; wherefore, dispute not because ye see not, for ye receive no witness until after the trial of your faith..." (Book of Mormon Ether 12:6)

"...For if there be no faith among the children of men God can do no miracle among them..." (Book of Mormon Ether 12:12)

Even though Moses writes of those amongst the children of Israel that murmured, there must have been those that continued in great faith for we witness a myriad of miracles amongst them such as -

"...the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:
22 He took not away the pillar of the cloud by day, nor the pillar of fire by night, from before the people." (Old Testament Exodus 13:21 - 22)

"...Moses stretched out his hand over the sea; and the LORD caused the sea to go back by a strong east wind all that night, and made the sea dry land, and the waters were divided.
22 And the children of Israel went into the midst of the sea upon the dry ground: and the waters were a wall unto them on their right hand, and on their left." (Old Testament Exodus 14:21 - 22)

"And Moses stretched forth his hand over the sea, and the sea returned to his strength when the morning appeared; and the Egyptians fled against it; and the LORD overthrew the Egyptians in the midst of the sea.
28 And the waters returned, and covered the chariots, and the horsemen, and all the host of Pharaoh that came into the sea after them; there remained not so much as one of them." (Old Testament Exodus 14:27 - 28)

"And Israel saw that great work which the LORD did upon the Egyptians: and the people feared the LORD, and believed the LORD, and his servant Moses." (Old Testament Exodus 14:31)

And even as the people murmured in the wilderness -

"...the LORD spake unto Moses, saying,
12 I have heard the murmurings of the children of Israel: speak unto them, saying, At even ye shall eat flesh, and in the morning ye shall be filled with bread; and ye shall know that I am the LORD your God." (Old Testament Exodus 16:11 - 12)

"And it came to pass, that at even the quails came up, and covered the camp..." (Old Testament Exodus 16:13)

"...and in the morning the dew lay round about the host.
14 And when the dew that lay was gone up, behold, upon the face of the wilderness there lay a small round thing, as small as the hoar frost on the ground.
15 And when the children of Israel saw it, they said one to another, It is manna: for they wist not what it was. And Moses said unto them, This is the bread which the LORD hath given you to eat." (Old Testament Exodus 16:13 - 15)

Moroni continued that even -

"...by faith was the law of Moses given." (Book of Mormon Ether 12:11)

But notwithstanding miracles or signs -

"Wherefore, whoso believeth in God might with surety hope for a better world, yea, even a place at the right hand of God, which hope cometh of faith, maketh an anchor to the souls of men, which would make them sure and steadfast, always abounding in good works, being led to glorify God." (Book of Mormon Ether 12:4)

"Wherefore, ye may also have hope, and be partakers of the gift, if ye will but have faith." (Book of Mormon Ether 12:9)