Ischuos is translated here as "might." Ischuos conveys the picture of a very, very strong man, such as a bodybuilder or a mighty man with muscular capabilities. If you look in the verse above, you see that Paul is attributing Ischuos power to God, not to any human. Paul sees God as One who is able, mighty and muscular.
It is Ischuos that is backing up Kratos. Kratos, if you remember is the outwardly manifested, eruptive power of God. Ischuos is the force that works behind the Kratos power.
All that God is, all the power He possesses, and all the energy of His muscular, mighty ability now energizes the Kratos power that is at work within you. With this power at your disposal today, you can confront the unseen demonic spirits that come to wage war against your flesh and your soul -- and you can win every time! Since this power is available to you today, you are ready to lay hands on the sick, pray with power and authority, speak God's Word in every situation, and see mountains move on your behalf!
So the next time that you run into a problem that seems a little overwhelming, remind yourself that "...greater is He that is in you than He that is in the world." You have no need to be afraid and no need to shrink back in timidity, for there's enough power at work in you to resist ANY force that comes against you and to supernaturally remedy anything that need to be changed!
Taken from Sparkling Gems from the Greek (pg 348-350).
BE A MAN.