I wrote the following to a friend a while back, but I wanted to share what I wrote about the verse here:

Ephesians 3:20 says, "Now unto him [God] that is able to do abundantly and exceedingly above all we ask or think, according to the power that worketh in us." 

So God can do more than we could ever imagine, according to the power that works in us. What is the POWER that works in us? 

I'll answer that question by quoting another scripture. Acts 10:38 "And you know that God anointed Jesus of Nazareth with the Holy Spirit and with POWER. Then Jesus went about doing good and healing all that were oppressed by the devil, for God was with him." 

What does this verse say about where Jesus' power came from? It came from the anointing of the Holy Spirit. 

Before Jesus ascended into to heaven after His resurrection, He talked with His disciples. He gave them instructions about what He wanted them to do. In Acts 1:8 Jesus said, "But you will receive POWER when the Holy Spirit comes upon you, and you will be my witnesses...." 

Jesus had told them previously that the Holy Spirit would come to the earth after He went away. He explained that He had to go away, or else the Holy Spirit couldn't come, but once He left, then the Holy Spirit would come. We can read about that in John chapter 16. I won't type out the whole chapter, but I will quote verse 7 where it says this, "But in fact, it is best for you that I go away, because if I don't, the Advocate [The Holy Spirit] won't come. If I do go away, then I will send him to you." 

Let's go back to the verse I talked about earlier: Ephesians 3:20 says, "Now unto him [God] that is able to do abundantly and exceedingly above all we ask or think, according to the POWER that worketh in us." 

So the power that works in us is the Holy Spirit. God poured out the Holy Spirit on the earth in Acts chapter 2. I will quote the first few verses of that chapter:

Acts 2:1-4 "On the day of Pentecost all the believers were meeting together in one place. (2) Suddenly, there was a sound from heaven like the roaring of a mighty windstorm, and it filled the house where they were sitting....(4) And everyone present was filled with the Holy Spirit." 

So it is through the power of the Holy Spirit living in us, that God is able to do exceedingly and abundantly all we ask or think. 

However, we have to know how to release that power.  People often think that Jesus could do miracles on the earth because He was God, but Philippians 2:6-7 tells us, "Though he was God, he did not think of equality with God as something to cling to.  (7) Instead, he gave up his divine privileges, he took the humble position of a slave asn was born a human being."  Jesus was stripped of his Godly powers when He became man. Notice that Jesus never did anything supernatural until after He was anointed with the Holy Spirit, and that's when He started to perform miracles.

Again I ask, how did Jesus release the power of the Holy Spirit?   Jesus released the power by speaking to things and commanding them to happen. His disciples also did that same thing. He even told them in Mark 11:22-24 "Then Jesus said to the disciples, 'Have faith in God. (23) I tell you the truth, you can SAY to this mountain, 'May you be lifted up and thrown into the sea', and it will happen, but you must really believe it will happen, and have no doubt in your heart. (24) I tell you, you pray for anything, and if you believe that you received it, it will be yours."

Back in those days, they called problems "mountains" so Jesus was not talking about a literal mountain here, he was saying speak to your problem, and tell it what to do, and if you believe in your heart and have no doubt, and you believe right then and there that you will receive it, then it will be yours. He called "speaking to the mountain" praying. That's how you release the power of the Holy Spirit inside of you, by speaking. It may sound crazy, but that's what Jesus did, He said, "Lazarus come forth" and raised him from the dead, He said "Be still" and calmed the storm. In Acts chapter 3:6 Peter spoke to the man that was crippled from birth and said, "....In the name of Jesus Christ the Nazarene, get up and walk." and the man did and he was healed. 

I speak to my body and tell it to heal. I have a whole list of confessions that I speak over myself every day. I will just share a few with you, just so you can understand what I mean by speaing to things to release the Holy Spirit's power:

1. Body, I speak the Word of Faith to you. I demand that every organ perform a perfect work, for you are the temple of the Holy Spirit; therefore, I charge you in the name of Jesus Christ and by the authority of His Holy Word to be healed and made whole in Jesus name. (Prov. 12:18.)

2. Father, I resist the enemy in every form that he comes against me--I require my body to be strong and healthy, and I enforce it with Your Word. I reject the curse, and I enforce life in this body. (James 4:7.)

3, I will not die but live and declare the works of the God. (Ps. 118:17).

Pair Ephesians 3:20 with:

John 14:12 "I tell you the truth, anyone who believes in me will do the same works I have done, and even greater works than these, because I am goint to be with my the Father."

Mark 16:15-18  "....God into all the world and preach the Good News to everyone.  (16) Anyone who believes and is baptized will be saved....(17) These miracles and signs will accompany those that believe: They will cast out demons in my name, and they will speak in new languages. (18) They will be able to handle snakes with safety, and if they drink anything poisonous, it won't hurt them.  They will be able to place their hand on the sick, and they will recover."  

Revelation 12: 11 "And they overcame him by the the blood of the lamb, and by the  WORD of their testimony...."