There are some equipments that wouldn't work unless the current source is DC. An AC current wouldn't power it hence the AC must be converted to DC if it must power such circuits which a rectifier does, it converts AC to DC. In spite of AC becoming DC, it isn't pure DC yet as it still contains ripples and AC components hence the efficiency will be poor hence filters help clean off the ripples to make it fully DC by eliminating every trait of AC. If we are going to walk in the plans and purposes of God, it starts from being saved. An unsaved man cannot walk in the plans of God fully but will miss a large chunk of God's dreams and can't fully utilize the fragrance God wants to endow on him towards lives just in the same manner AC cannot power some equipments hence must be converted to DC.
AC is sinusoidal hence is not constant. At this instantaneous time, it is positive, at another instantaneous time it is zero at another it is negative. Such instability and unpredictability isn't seen in DC which is always in one direction. It is as we are converted from the life of the world(the human nature), that there is more stability and direction to our lives. One of the characteristics of the life of the world is instability. Its a world of competition and no peace hence like a rat race with no fixed direction but influenced by all men. Jesus gives peace and calmness and He wants to be our greatest influence. The fact that an AC has been converted to DC by rectifiers doesn't mean its fully a DC yet as it still contains some AC components which must be eliminated if it must be pure DC. Though we have been converted from the life of the world and have received the life of God hence can flow and walk with Him, our bodies and minds are not born again. These too need to be worked upon as they can cause great impediment in our walk with God and reduce our efficiency in the same manner AC components do in DC unless they are filtered off.
Though we are like DC after conversion from the uncertainty of AC, it must be filtered hence God's Word is to renew our minds which is not born again. We are to allow the life of God found in our spirit to flow into our minds which invariably will flow into our bodies. Failure to renew our minds will cause great hindrance in our walk with God. We walk in the fullness of God when our minds are brought to the same state with our spirit as our spirit is brought into the same state with God. Addictions and different strong holds are in the mind. It is by renewing the mind with the Word of God and fellowship with God the mind will let go hence smooth flow with God as pure DC hence can power equipments without hindrance and what we are in the public is who we really are and not hypocrite