Jesus filled this two roles. He was the lamb of God and also the lion of the tribe of Judah.
In the first case, he was the lamb of God in the sense that he is the one that God has lovingly provided to be sacrificed for the atonement of the Adamic sin, the sin that has resulted to the death of all mankind. At one occasion, when John the baptizer saw Jesus coming to be baptized by him he exclaimed,'see the lamb that takes away the sins of the world'--John 1:29.
Now, the lion is a symbol of courageous justice. God, at times likens himself to a lion in executing judgement against law-defying peoples of the old. Jesus was from a small tribe of Israel called Judah and is God's chief judicial officer who is and will be used by to God in executing his(God's) judgement and vengeance against lawless nations and peoples. That is why John the latter in his visions refereed to Jesus as "the Lion that is of the tribe of Judah"--Rev 5:5.
I hope this helps.
Justin.. Cyprus
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