I'm glad you asked this question. It's an age old question which many people have grappled with. This, in coincidence with the philosophical question of the Problem of Evil. A Thread: https://twitter.com/oswaldtheson/status/1249284342716796928

This question begs a false dichotomy/dilemma. It presupposes that God has to make a choice between Love and Justice. ie, if God punishes, then He does not love and vice versa. The justice of God is proven in that He punishes sin. The love of God is

proven, in that He punished His son in our place. The marriage between love and justice produces mercy, and that is what the world experiences everyday. That is why the next scripture you posted had to do with Christians loving their enemies and praying for them

In doing that, we show mercy just as God has shown mercy to us. In fact, the Bible says in Matthew 5 that "Blessed are those who are merciful, for they shall be shown mercy". Nevertheless, it is possible to divorce justice and love.

This is how we do so: Love, in its simplest definition, is to will the good of another. Justice, in its simplest definition, is to reward good and punish evil. Now, if the loved is unwilling to become good, mercy will not work for the person. (Hebrews 10:26)

When mercy no longer operates, justice then reveals itself in full glory. Remember that sin existed even before man was created. And God punished sin even before man was created. God punished the devil and his angels. If God punished them too, whom He loved,

we will also not escape punishment. It would be absurd to believe that God wouldn't punish the devil. There is nothing like repentance after we leave earth. Sin has the power to transform us into different creatures, and this new negative identity has eternal ramifications.

Think of Lucifer turn Satan.... After he sinned, he became another creature altogether. Because, as I hope we both know, sin is not just an act, it is a nature. Now, if something is eternally corrupted, it is eternally condemned.