Ah, I've thought much of this question and my conclusion-you don't. Christ promises that we will bear much fruit but how does any of us really know what fruit we are bearing? An evangelist might be able to calculate the number of "souls" he saves but what about others? And what "fruit" are we talking about anyway. When our Lord told those to enter the kingdom because...their response was "When did we do these things?"
At the end of the day God wants us to have faith in His promises. That includes that He has redeemed us, He has saved us, He will cause us to persevere, He will glorify us, and He will cause us to bear much fruit. We rest upon His promises that what He has accomplish He will bring to completion.
It's a matter of faith and trust; not a matter of taking a wafer every Sunday. Some may want more assurance of heaven. It comes down to faith in God.
Hey Harley, long time no speak.
Just a bump to your excellent words.