Today I answer the question from Fhamous Whan, “How can a merciful God create hell?”

How? He spoke it into existence. If you really meant to ask why?, then let scriptures explain.

The problem most people have is they do not know the God of the Bible. The God that they believe in is one of their own imaginations and is restricted by their morality.

The God of the scriptures has approximately 25 attributes detailed in the Bible. These 25 attributes are EQUAL in God's nature and perfect in their application. Meaning that God's love, mercy, longsuffering, kindness, goodness, forgiveness, and grace does not overrule His righteousness, holiness, justice, and righteous just judgment. Listen to the LORD Himself as He explains this to Moses.

5 Now the LORD descended in the cloud and stood with him there, and proclaimed the name of the LORD. 6 And the LORD passed before him and proclaimed, "The LORD, the LORD God, merciful and gracious, longsuffering, and abounding in goodness and truth, 7 keeping mercy for thousands, forgiving iniquity and transgression and sin, BY NO MEANS CLEARING THE GUILTY, visiting the iniquity of the fathers upon the children and the children's children to the third and the fourth generation." Exodus 34:5-7

Just in case some get the erroneous idea that God punishes the children for their parents sins, He provide clarity to the prophet Ezekiel.

1 The word of the LORD came to me again, saying, 2 "What do you mean when you use this proverb concerning the land of Israel, saying: 'The fathers have eaten sour grapes, and the children's teeth are set on edge'? 3 "As I live," says the Lord GOD, "you shall no longer use this proverb in Israel. 4 "Behold, all souls are Mine; The soul of the father as well as the soul of the son is Mine; THE SOUL WHO SINS SHALL DIE. Ezekiel 18:1-4

There is one more thing we must understand before I show you why God created hell from the scriptures.

The LORD God is a Potentate! A Monarch! A King! He does not operate on a democratic process neither does He take advice. The LORD God is only does that which pleases Himself, for His satisfy His own purposes, WHICH SOLE PURPOSE IS TO BRING HIMSELF GLORY!

14 that you keep this commandment without spot, blameless until our Lord Jesus Christ's appearing, 15 which He will manifest in His own time, He who is the blessed and only POTENTATE, the King of kings and Lord of lords, 16 who alone has immortality, dwelling in unapproachable light, whom no man has seen or can see, to whom be honor and everlasting power. Amen. 1 Timothy 6:14-16

34 At the end of that time, I, Nebuchadnezzar, raised my eyes toward heaven, and my sanity was restored. Then I praised the Most High; I honored and glorified him who lives forever. His dominion is an eternal dominion; his kingdom endures from generation to generation. 35 ALL THE PEOPLES OF THE EARTH ARE REGARDED AS NOTHING. HE DOES AS HE PLEASES WITH THE POWERS OF HEAVEN AND THE PEOPLES OF THE EARTH. NO ONE CAN HOLD BACK HIS HAND OR SAY TO HIM: “WHAT HAVE YOU DONE?” Daniel 4:34-35

13 "But He is unique, and who can make Him change? And WHATEVER HIS SOUL DESIRES, THAT HE DOES. Job 23:13

3 But our God is in heaven; HE DOES WHATEVER HE PLEASES. Psalms 115:3

12 Who has measured the waters in the hollow of His hand, measured heaven with a span and calculated the dust of the earth in a measure? Weighed the mountains in scales and the hills in a balance? 13 Who has directed the Spirit of the LORD, or as His counselor has taught Him? 14 With whom did He take counsel, and who instructed Him, and taught Him in the path of justice? Who taught Him knowledge, and showed Him the way of understanding? 15 Behold, the nations are as a drop in a bucket, and are counted as the small dust on the scales; look, He lifts up the isles as a very little thing. 16 And Lebanon is not sufficient to burn, nor its beasts sufficient for a burnt offering. 17 All nations before Him ARE AS NOTHING, and THEY ARE COUNTED BY HIM LESS THAN NOTHING AND WORTHLESS. 8 To whom then will you liken God? Or what likeness will you compare to Him? Isaiah 40:12-18

Last one.
21 Do you not know? Have you not heard? Has it not been told you from the beginning? Have you not understood since the earth was founded? 22 He sits enthroned above the circle of the earth, and its people are like grasshoppers. He stretches out the heavens like a canopy, and spreads them out like a tent to live in. 23 He brings princes to naught and reduces the rulers of this world to nothing. Isaiah 40:21-23

Now God declares without reservation that He created all things and takes full responsibility for it.
4 The LORD has made all for Himself, Yes, even the wicked for the day of doom. Proverbs 16:4

 30 For the wicked are reserved for the day of doom; They shall be brought out on the day of wrath. Job 21:30

6 If a trumpet is blown in a city, will not the people be afraid? If there is calamity in a city, will not the LORD have done it? Amos 3:6

12 "If I were hungry, I would not tell you; for the world is Mine, and all its fullness. Psalms 50:12

41 "Then He will also say to those on the left hand, 'Depart from Me, you cursed, into the everlasting fire PREPARED FOR THE DEVIL AND HIS ANGELS: Matthew 25:41

Now let's answer the question, why did God create hell? The answer is to fully reveal His attributes, to execute His reconciliation plan, and to reveal His Redeemer, Christ Jesus the Lord.
14 What then shall we say? Is God unjust? Not at all! 15 For he says to Moses, “I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.” 16 IT DOES NOT, THEREFORE, DEPEND ON HUMAN DESIRE OR EFFORT, BUT ON GOD’S MERCY. 17 For Scripture says to Pharaoh: “I raised you up for this very purpose, that I might display my power in you and that my name might be proclaimed in all the earth.” 18 Therefore God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden.
19 One of you will say to me: “Then why does God still blame us? For who is able to resist his will?” 20 But who are you, a human being, to talk back to God? “Shall what is formed say to the one who formed it, ‘Why did you make me like this?’” 21 DOES NOT THE POTTER HAVE THE RIGHT to make out of the same lump of clay some pottery for special purposes and some for common use? 22 WHAT IF GOD, ALTHOUGH CHOOSING TO SHOW HIS WRATH AND MAKE HIS POWER KNOWN, bore with great patience the objects of his wrath—PREPARED FOR DESTRUCTION? 23 WHAT IF GOD DID THIS TO MAKE THE RICHES OF HIS GLORY KNOWN to the objects of his mercy, WHOM HE PREPARED IN ADVANCE for glory — 24 even us, WHOM HE ALSO CALLED, not only from the Jews but also from the Gentiles? Romans 9:14-24

3 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, 4 JUST AS HE CHOSE US IN HIM BEFORE THE FOUNDATION OF THE WORLD, that we should be holy and without blame before Him in love, 5 HAVING PREDESTINED US TO ADOPTION AS SONS BY JESUS CHRIST TO HIMSELF, ACCORDING TO THE GOOD PLEASURE OF HIS WILL, 6 TO THE PRAISE OF THE GLORY OF HIS GRACE, by which HE MADE US ACCEPTED in the Beloved. Ephesians 1:3-6
11 In Him (CHRIST) also we (TRUE BELIEVERS THAT GOD CALLED) have obtained an inheritance, BEING PREDESTINED ACCORDING TO THE PURPOSE OF HIM WHO WORKS ALL THINGS ACCORDING TO THE COUNSEL OF HIS WILL, 12 that we who first trusted in Christ SHOULD BE TO THE PRAIS OF HIS GLORY. Ephesians 1:11-12

There you have it my friend, straight from God Himself. Hope that helps.