Summary: Our view of God depends upon our perspective. Sinners see God as vengeful; saints see God as a refuge. Thus, our relationship to God determines how we view Him.
“The LORD is a jealous and avenging God;
the LORD is avenging and wrathful;
the LORD takes vengeance on his adversaries
and keeps wrath for his enemies.
The LORD is slow to anger and great in power,
and the LORD will by no means clear the guilty.
His way is in whirlwind and storm,
and the clouds are the dust of his feet.
He rebukes the sea and makes it dry;
he dries up all the rivers;
Bashan and Carmel wither;
the bloom of Lebanon withers.
The mountains quake before him;
the hills melt;
the earth heaves before him,
the world and all who dwell in it.
“Who can stand before his indignation?
Who can endure the heat of his anger?
His wrath is poured out like fire,
and the rocks are broken into pieces by him.
The LORD is good,
a stronghold in the day of trouble;
he knows those who take refuge in him.
But with an overflowing flood
he will make a complete end of the adversaries,
and will pursue his enemies into darkness.” 
Abrupt! Precipitous! Unexpected! Reading the opening words of Nahum’s Prophecy will almost give the reader whiplash. The Prophet opens the brief prophecy by pointing to the perception of God’s character as seen by the wicked. The character of God is terrifying to those who are determined to pursue their own desires. Then, without so much as even a nod to the fact that he is transitioning, the Prophet of God abruptly speaks of the way God appears to those who look to Him for refuge. Confusing? Only for those who have never met the Living God.
The wicked seldom think of God, or if they do think of Him, the thought is fleeting, transient. Simply thinking of God does not cause wicked people to reconsider their actions. However, their lack of perception and failure to consider the cost to themselves to do what is evil does not change their perception when they meet God.
God has described Himself in His Word by pointing to various qualities. He presents Himself as “faithful” [e.g. 1 CORINTHIANS 10:13], as “compassionate and merciful” [e.g. JAMES 5:11] and as “good” [e.g. 1 PETER 2:3]. Of course, we have all read that God is “light” [e.g. 1 JOHN 1:5] and that He is “love” [e.g. 1 JOHN 4:8]. God is just, according to what is revealed in HEBREWS 6:10. For all these positive representations of the Lord, we who are twice-born are also aware that “the Lord is an avenger” [1 THESSALONIANS 4:6], and that “our God is a consuming fire” [HEBREWS 12:29]. These latter depictions are aimed at professing believers, cautioning us not to presume against the Lord God.
God wants His people to know Him in the fullness of His goodness. However, knowing His character, we are cautioned not to presume against Him. At the same time, Jesus’ words to His disciples comfort those who follow Him and terrify those who turn from Him. Jesus warns, “I tell you, my friends, do not fear those who kill the body, and after that have nothing more that they can do. But I will warn you whom to fear: fear him who, after he has killed, has authority to cast into hell. Yes, I tell you, fear him! Are not five sparrows sold for two pennies? And not one of them is forgotten before God. Why, even the hairs of your head are all numbered. Fear not; you are of more value than many sparrows” [LUKE 12:4-7].
To sinners, the character of God is dreadful when they at last witness His awesome power in judgement. We see the final actions of bold sinners in John’s vision, the Apocalypse. Listen to these frightful words as John recorded them of what shall take place on the earth during the days of the Great Tribulation when God begins to judge the earth. “When [the Lamb of God] opened the sixth seal, I looked, and behold, there was a great earthquake, and the sun became black as sackcloth, the full moon became like blood, and the stars of the sky fell to the earth as the fig tree sheds its winter fruit when shaken by a gale. The sky vanished like a scroll that is being rolled up, and every mountain and island was removed from its place. Then the kings of the earth and the great ones and the generals and the rich and the powerful, and everyone, slave and free, hid themselves in the caves and among the rocks of the mountains, calling to the mountains and rocks, ‘Fall on us and hide us from the face of him who is seated on the throne, and from the wrath of the Lamb, for the great day of their wrath has come, and who can stand” [REVELATION 6:12-17]?