Joel 1 - 3

Of the first visit of Moroni to the Prophet Joseph Smith, Joseph later records the Moroni -

"...also quoted the second chapter of Joel, from the twenty-eighth verse to the last. He also said that this was not yet fulfilled, but was soon to be..." (Pearl of Great Price JS-History 1:41)

As Peter standing with the eleven on the Day of Pentacost -

"...suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting.
3 And there appeared unto them cloven tongues like as of fire, and it sat upon each of them.
4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
5 And there were dwelling at Jerusalem Jews, devout men, out of every nation under heaven.
6 Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language.
7 And they were all amazed and marvelled..." (New Testament Acts 2:2 - 7)

Then -

"...Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judæa, and all ye that dwell at Jerusalem, be this known unto you, and hearken to my words:
15 For these are not drunken, as ye suppose, seeing it is but the third hour of the day.
16 But this is that which was spoken by the prophet Joel..."(New Testament Acts 2:14 - 16)

It becomes apparent that the words of Joel are of great importance as he prophecied in the latter-days -

"...it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions..." (Old Testament Joel 2:28)

The Spirit will not be restricted to a few but even -

"...upon the servants and upon the handmaids in those days will I pour out my spirit." (Old Testament Joel 2:29)

And with the pouring out of his Spirit the Lord promises -

"...I will shew wonders in the heavens and in the earth, blood, and fire, and pillars of smoke.
31 The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the LORD come." (Old Testament Joel 2:30 - 31)

It becomes clear that it will be a "terrible" day for the wicked, but for the righteous it will be a great day -

"And it shall come to pass, that whosoever shall call on the name of the LORD shall be delivered: for in mount Zion and in Jerusalem shall be deliverance, as the LORD hath said, and in the remnant whom the LORD shall call." (Old Testament Joel 2:32)

And they will be delivered as -

"The LORD also shall roar out of Zion, and utter his voice from Jerusalem; and the heavens and the earth shall shake: but the LORD will be the hope of his people, and the strength of the children of Israel.
17 So shall ye know that I am the LORD your God dwelling in Zion, my holy mountain: then shall Jerusalem be holy, and there shall no strangers pass through her any more." (Old Testament Joel 3:16 - 17)

"Therefore also now, saith the LORD, turn ye even to me with all your heart, and with fasting, and with weeping, and with mourning:
13 And rend your heart, and not your garments, and turn unto the LORD your God: for he is gracious and merciful, slow to anger, and of great kindness, and repenteth him of the evil."
(Old Testament Joel 2:12 - 13)