When we trust Christ we are complete. Like the box we got Saturday there was a complete table and four complete chairs in that box. As believers we need to grow to understand what we have in Christ and how he has gifted us so that we can serve Him most effectively. That does not change the fact that we are complete. It just makes us live in that state of completeness more fully. The pieces I assembled were the same before and after the assembly. They did not change they were just rearranged. They would have been a table and four chairs whether I assembled them or not.
At the bottom of the instructions there was a suggestion that we needed to continually check the hardware or the table and chairs could cease to function. For us that is a really good suggestion. Christ tells us that we need to abide in Him, John 15:5. If we do not do that regularly, we will cease to function. We will still be complete, like the table and chairs. We just will not be very effective.