Does this mean He will help us overcome difficulties in this life? Ephesians 3:20 - "Now unto him that is able to do exceeding abundantly above all that we ask or think, according to the power that worketh in us"...

I, at first, read this as being about Heaven. A lady in a church in leeds said it was about Him strengthening us now, in this age. Correct?
Since neither view is stated explicitly in the text nor can be inferred from the context, there's no definitive answer, however the use of present tense, and the next verse:


  21to him be glory in the church and in Christ Jesus throughout all generations, for ever and ever! Amen.


To me indicate that his ability and power are available to us now.