God is not the same as us. He is omniscient and has the ability and right to judge. We do not have the ability to really know the heart of a person and therefore do not have the right to judge and are required to deal justly within our fallen limitations. God does know perfectly and he judges perfectly given his perfect knowledge.
By that logic, do you believe that if we come to know that our enemy is really evil then its okay not to love them?
I don't remember that command coming with this qualification...in fact the command seems to presume that the enemy is indeed evil ("those who wrong you") but still our response should be to do good to them and love them.
I guess we don't need to follow God's example on this particular point, but just do as He says?
John 3:16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
I believe that the Holy Spirit said what He meant and meant what He said when He inspired John to pen this verse.
But...God is also just and must punish disobedience to the gospel.
People aren't in hell because God doesn't love them.
They are there because they disobeyed the gospel of Christ and have received the just penalty.
The wages of sin is death.
According to Revelation 6:9-11 there are souls looking forward to God judging their enemies.
Revelation 6:9-11
9When the Lamb broke the fifth seal, I saw underneath the altar the souls of those who had been slain because of the word of God, and because of the testimony which they had maintained; 10and they cried out with a loud voice, saying, “How long, O Lord, holy and true, will You refrain from judging and avenging our blood on those who dwell on the earth?” 11And there was given to each of them a white robe; and they were told that they should rest for a little while longer, until the number of their fellow servants and their brethren who were to be killed even as they had been, would be completed also.
God has sworn that he will repay.
Romans 12:19
19 Do not take revenge, my friends, but leave room for God's wrath, for it is written: "It is mine to avenge; I will repay," says the Lord.
So we wil rejoice in God's judgement on the wicked. His judgements are holy and his people will rejoice in the goodness of them. Hell is just punishment for the wicked and all of heaven will glorify God for his judgement.