This is David talking. He got rid of his enemies thoroughly! We should do the same.
I'm not talking about human ones, ones we can see. Our enemies are unseen in the invisible realm. Check out Ephesians 6:12:
12For our W)'>(W)struggle is not against X)'>(X)flesh and blood, but Y)'>(Y)against the rulers, against the powers, against the Z)'>(Z)world forces of this AA)'>(AA)darkness, against the AB)'>(AB)spiritual forces of wickedness in AC)'>(AC)the heavenly places.
Why do we have to make sure we destroy our enemies? If we don't they will come back and bite us in the butt or hit us on the head or somehow cause us pain and frustration. They will torment us until they are gone. God's given us the strength to destroy them. God + you is a majority. There is nothing stronger than God. There is no spiritual power which can defeat you when you're relying on God.
Maybe you don't know what your enemy is. Think back on your life. What is the thing you've struggled with again and again? Maybe there's several. Maybe there is just one. Those areas are the enemy. Those areas will continue to torment you until you have victory in them.
One of my enemies is the fear and apparent reality of inadequate finances. I remember worrying about it in college. How would I pay what I needed to pay? And it got even worse when I got married. Now it was not just me but a bunch of children that needed to be taken care and a house to pay for and care for.
Over and over God has shown Himself faithful in this for me. After I'd been married for eight months or so we were expecting our first child. Both my husband and I were in the army stationed at Fort Bragg. If you've been in the service or are in the service you know you can be deployed at any moment. At Fort Bragg we had to be ready to go in 18 hours. I didn't want to do this to a child. So I knew I needed to get out. During the nine months of pregnancy I prayed and prayed. On my husband's salary there was no way we could make it. He paid a lot in child support and we both had car payments. After these were taken out we had $300 left for the month (before paying rent which was $350 and utilities and food and everything else). But I talked to God about Moses mom. She got paid to be his mom! And so I asked God to make it possible for me to stay home with my not-yet-born baby.
That baby will be 16 years old this summer. And we have five more children younger than him. I've never had to work outside the home. It's been hard but God has made it possible. I've made money writing several times. I've freelanced. Sometimes we had no clue how things would be taken care of (that has been most of the time and still is) but God came through.
(Working outside the home is a good thing if you can do it. For our family situation it just doesn't work, mainly right now due to my 11 year old son's disabilities.)
And we've seen God do financial miracles in other ways too (paid for two adoptions which were mighty expensive).
But, this enemy has not yet been defeated because I still deal with it. God wants it destroyed. God wants me to have belief no matter what in this area. I think actually God wants to do something cool in this area through me.
Think about the area that is your enemy. I am guessing whatever that area is could end up being an area of strength and ministry for you to others through God. This is why it is attacked so much.
We gotta hang on to God and keep facing and attacking our enemies in anyway we can until they no longer torment us. Then, God will use that area in a mighty way. I know this is true.