Yeshua the Messiah gave his disciples the following command

Matthew 5:44-45 [Hebrew Gospels from Sepharad]
44 And I say unto you, you must love your enemies and do good to those that who do evil to you, and pray for your persecutors
45 in order that you may be sons of your Father...                                                                                              (Words of Yeshua in purple)

As followers of the Nazarene, we are to love everyone, friends and enemies. This is in accordance with the Torah see Exodus 23:4-5.

Yeshua continues 

Matthew 5:44-45 [The Scriptures - TS]
46  “For if you love those loving you, what reward have you? Are the tax collectors not doing the same too?                                                                                                                                                                 (Tax collectors were considered evil or wicked in Yeshua's day because they worked for the Romans)

How should we treat our enemies? Well, maybe we first need to know: Who are our enemies?

The Cambrige Dictionary defines the word ‘enemy’ as

a person who hates or opposes another person and tries to harm them or stop them from doing something

The range of the word stretches from someone who is just unfriendly to you to someone who wishes to harm or even kill you.
The difference between children of the Eternal and the children of the adversary is stated in

1 John 3:10-11 [TS]
10  In this the children of Elohim and the children of the devil are manifest: Everyone not doing righteousness is not of Elohim, neither the one not loving his brother. 
Love One Another
11  Because this is the message that you heard from the beginning, that we should love one another,

The Jewish attitude of hatred towards Yeshua was foretold in

Psalms 69:4
4  Those who hate me without a cause are more than the hairs of my head; they are mighty who would destroy me, My lying enemies
(See Psalms 35:19; John 15:25)

How do we show love for our enemies? We are not left in the dark about this, for Yeshua explains:

Luke 6:27-28
27  “But I say to you who are hearing: Love your enemies, do good to those hating you. 
28  “Bless those cursing you, and pray for those insulting you. 

Yeshua’s statement is within the context of the Golden Rule,

Luke 6:31
 “And as you wish men should do to you, you also do to them in the same way.

So, Yeshua taught what we must continuously love those who are unfriendly or hate us. This is a positive matter; Yeshua, in other words, tells us to do good unto everyone. 

We could divide this subject into two parts: the negative and the positive. In other words, there are some things we would not do to our enemy; and, there are some things that we do to our enemies. This is not difficult to understand:
First, what is it that you do not want others doing to you? For example, do you like it when someone speaks ill of you, using derogatory terms? Well, then, do not do these to others. Second, what is it you wish people would do to you? Treat you respectfully when you disagree with their beliefs? Then, do that to them.

 If one is a Nazarene, one who claims to follow the teachings of Yeshua the Nazarene, then how should you respond to those who are now unfriendly? Certainly using language that is derogatory, untrue, without foundation, extremely exaggerated, or even slanderous does not conform to our Master’s instructions above.

Shaul (Paul) advises us:

Colossians 4:6 [Christian Scriptures 2001]
Always speak graciously, seasoned with salt, aware of how you are obligated to answer each person.

And Kepha (Peter) writes in a similar manner:

1 Peter 3:15-16 [Hebraic Roots Bible]
15 But sanctify the Messiah as Sovereign in your hearts, and always be ready to give an answer to everyone asking you a reason concerning the hope of your faith, with meekness and fear,
16 having a good conscience, that while they speak against you as evildoers, they may be shamed, those falsely accusing your good behaviour in Messiah.

To observe our Master’s words to love our enemies may be observed by refusing to speak in a derogatory manner about others. 
In the end, even those unfriendly to us will see that Messiah has truly taken up residence in our hearts. This may work to move their conscience to change their attitude.

Shaul writes to the Romans:

Romans 12:17-21
17  Repay no one evil for evil. Respect what is right in the sight of all men. 
18  If possible, on your part, be at peace with all men. 
19  Beloved, do not revenge yourselves, but give place to the wrath, for it has been written, ”Vengeance is Mine, I shall repay,” says יהוה. (Deuteronomy 32:35) 
20  “Instead, if your enemy hungers, feed him; if he thirsts, give him a drink, for in so doing you shall heap coals of fire on his head.” (Proverbs 25:21-22) 
21  Do not be overcome by evil, but overcome evil with good. 

Mark Heber Miller; Christian Scriptures 2001 © Mark Heber Miller