Christians know Jesus and thus, they know His love. But many people don’t understand His love, biblically.
Others who aren’t saved, if they know nothing else in the Bible, they know the verse “God is love” from 1 John 4:8…which they use to reject any discussion of sin, wrath, or judgment, half the Gospel. But unsaved people can’t love (in a Christ-like, God-honoring way). (1 John 4:8)
So what does Apostle John mean when he writes ‘God is love’?
Here is a reposted essay from the blog at Grace To You explaining the verse.
“God is love” (1 John 4:8).
That’s a transcendent thought that finds its ultimate expression in the cross of Christ. The most famous verse in the Bible confirms that God’s love was the motive for sending Christ: “For God so loved the world . . .” (John 3:16).
But God’s love didn’t first appear two thousand years ago—that’s where it climaxed. The truth is that all of history bears the undeniable marks of God’s loving nature. From Genesis to Revelation, His great love is displayed on multiple levels and in countless glorious ways. In fact, His unchanging love is older than time itself.
God’s Love Before Time
John MacArthur points out that right from the beginning—in fact, before the beginning—God’s love was the driving force that set the scene for His creation:
In eternity past, within the perfect fellowship of the Trinity, God the Father purposed, as a love gift to His Son, to redeem a people who would honor and glorify the Son (cf. John 6:39; 17:9–15). Thus, though God existed in perfect Trinitarian solitude, He created a race of beings out of which He would love and redeem those who would in turn love Him forever. 
It’s overwhelming to consider that God’s plan of redemption originated in eternity past and that His predestined strategy is fueled by His great love (Ephesians 1:4–5).
God’s Love in Creation
God’s love is also on display in the perfect world He created for us. The creation account repeatedly features the phrase, “and God saw that it was good” (Genesis 1:10, 18, 21, 25; cf. 1:4, 31). And in His immense love, He created mankind as the capstone of His very good creation (Genesis 1:27–28). That theme continues throughout Scripture. The earth is full of God’s lovingkindness (Psalm 119:64). “The Lord is good to all, and His mercies are over all His works” (Psalm 145:9). “He did not leave Himself without witness, in that He did good and gave you rains from heaven and fruitful seasons, satisfying your hearts with food and gladness” (Acts 14:17).
But there was a greater purpose behind God’s creative work. He did not create the world as the main attraction, but as the theater where His redemptive plan would take place and His love would be put on display. Even the corrupting blight of sin on God’s creation is integral to the display of His love: His redeeming love would forever remain hidden without sinners to redeem.
God’s Love in Humanity
Furthermore, God’s love is also evident in the fact that He created people rather than robots. God is all powerful, all knowing, and perfectly capable of creating a race of creatures to do His bidding. But He is also relational and created man to reciprocate His love.
He designed sinners to know and love Him by an act of their wills (cf. John 7:17–18), though not apart from the work of His Spirit (cf. John 1:12–13; Ephesians 2:5; Titus 3:5). God’s greatest commandment is that people love Him with all their heart, soul, mind, and strength (Mark 12:29–30). 
What a privilege it is that we, as sinners, can actually enter into and enjoy a loving relationship with our Creator as His responsive creatures. God is under no obligation to reconcile with His rebellious subjects, but He is “rich in mercy, because of His great love with which He loved us” (Ephesians 2:4). His love is the means by which we can willfully love Him—“We love, because He first loved us” (1 John 4:19).
Is God’s Love Inconsistent?
But what about those who don’t love God? Is His love exclusive to Christians? Or does God love everyone equally? For many, those questions are vexing, as they wrestle with the theological implications of God’s love.
We recently brought those questions to John MacArthur. You can see what he had to say in the following video:
There is a universal aspect to God’s love. This general love of God for all people is most evident in the fact that He delays His wrath upon unrepentant sinners (Genesis 15:16; Acts 17:30–31; Romans 3:25). And while God’s saving love is exclusively bestowed on His elect, He powerfully displays His love for the whole world by offering the gospel to all people (Matthew 28:19).
But that general love of God is temporary—it extends no further than the Day of Judgment. By contrast, God’s saving love is exclusively and eternally lavished on those who believe. It is a love so glorious that the apostle Paul could scarcely contain his superlatives when describing it:
God, being rich in mercy, because of His great love with which He loved us, even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus, so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus. (Ephesians 2:4–7)
God is love. But His love is manifest in different ways over time, and bestowed according to His redemptive purposes. It’s a blessing to all men, but a comfort for only His elect.