Of the dozens of biblical texts about lions, most remind us of the strength, fierceness, and roar of these predators. There were lions in Israel during biblical times, and shepherds, farmers and travelers seem to have encountered them most often. The lion often attacked flocks unexpectedly, and was ruthless and usually unstoppable. The roar of the lion was audible for miles, but he was deadly silent when in attack mode.
Most of the references to the lion in the Scriptures are about his powerful voice (Job 4.10; Ps. 22.13; 104.21; Prov. 19.12; 28.15; Jer. 2.15,30; Ezek. 22.25; Hos. 11.10; Zech. 3.3; 11.3; Rev. 10.3). The usual response is fright and flight, and so it is not surprising that Amos 3.8 says "the lion has roared; who will not fear?" It is probable that far more persons had heard a lion than had seen one, and this only added to the imagined fierceness and strength of the animal.
Given these circumstances, it is no surprise that the lion was often used metaphorically in apocalyptic literature to refer to rulers, particularly strong or ruthless ones (see Ezek. 1.10; 10.14; Dan. 7.4). We frequently find lion gates in archaeological ruins, from the Hittite sites in Turkey to the Babylonian and Persian sites in Iraq, or the Assyrian and Egyptian sites. It was a popular symbol of royalty, and it is not a surprise that the lion was seen by many as the king of the predators, or even the king of all beasts. In fact we know that Ramses II and Asshurbanipal II kept live lions.
Nor is it surprising that even a small kingdom like Judah, as a part of its PR, would choose the lion as its symbol. In Gen 49.9, Jacob's blessing includes a reference to the tribe of Judah being like a lion. This text later became the basis of considerable messianic expectation and speculation in early Judaism (cf. 1QSb 5.29; 4 Ez. 12.31-33).
There are texts in 1 and 2 Kings which refer to God using lions as agents of divine punishment. There are even texts in which God's just actions are said to be lion-like: "I will rend and go away, I will carry off and none will rescue" (Hos. 5.14). Yet the lion is also an image of injustice or wickedness-the Psalmist says about evil humans that "like a lion they will tear me apart; they will drag me away with no one to rescue."
In the New Testament, even the Devil is seen as analogous to the lion, for we hear how he preys on people like a lion (cf. 1 Pet. 5.8; 2 Tim. 4.17). By no means, then, is the lion always used as an image of God, a good king, or goodness or majesty as abstract qualities in the Bible.
A king especially might be said to have the courage, strength, wrath like a lion (Prov. 20.2). And when a biblical writer wanted to conjure up the ultimate image of peace, would speak of a day when the lion would cease being a predator and lie down with the lamb (Is. 11.6).
That's why Revelation's image of Christ as both lion and lamb, almost melded together, is so remarkable. It is perhaps this last image which C.S Lewis had most in mind when he conjured up the wonderful character Aslan in the Chronicles of Narnia.
Although the dominant image of Jesus in the book of Revelation is the slain, but now triumphant lamb, its author does use the lion image. Revelation 5.5 says that the lion of the tribe of Judah has already triumphed, not through final judgment on the wicked, but rather through his atoning death which opens up the possibility for all to be saved. He is worthy to unseal the judgment scroll because he has already effected salvation through his death as the slain lamb of God who takes away the world's sin.