God Gives Us Strength . . .
Ephesians 6:10 is our New Testament scripture that complements this one in Isaiah.
"Be strong in the Lord, and the power of His might."
We have the Holy Spirit to give us the ability to Be strong in the Lord, and in the strength, or power, of His might. If we are strong in the Lord, He is our strength and might, and we no longer need to do everything in our own strength.
Ephesians goes on to say, "And having done all TO STAND."
In other words, pray, and put your trust in God (Proverbs 3:4-5) to see you through a difficult situation; He will direct you as to what to do and will give you ideas to carry out to resolve the situation.
When all that can be done is done then, having done all, stand firm in your faith that God will act according to the power of His might.
That power raised Jesus from the dead. It can do ANYTHING.
1 Corinthians 16:13 says, "Be on the alert, stand firm in the faith, act like men, be strong."
The rest of Ephesians chapter 6 is worth a read, because it shows us what our weapons as christians are, and most importantly, that our fight is not with the lousy neighbour down the road but it is spiritual.
The rest of that chapter in Isaiah says, "Though youths grow weary and tired, and vigorous young men stumble badly, yet those who wait for the Lord will gain new strength; They will mount up with wings like eagles, they will run and not get tired, they will walk and not become weary."
"Come to Me all who are weary and heavy laden and I will give you rest."  Matthew 11:28
"He gives strength to the weary, and to him who lacks might He increases power."  Isaiah 40:29