Like verse 19 says...We need to know the love of Christ and be filled with all the fulness of God. According to verse 20, God is able to do exceeding abundantly above all that we ask or think, according to the power that works in us.
There is a power working within us today as well. His name is the Holy Spirit. When we invited Jesus into our heart, the Holy Spirit came to dwell and we became one with Him. We need to be strong in the inner man and the only one that can help us is the Holy Spirit. When we are strong in the inner man, we will not be so quick to give in to the desires of the flesh. All we have to do is trust Him.
God always knows what He is doing and He is always on time, He's never late. He will come through for us if we let Him. So, when you find yourself saying or doing things you don't want to, ask God to strengthen you in the inner man.