Ultimately, as long as we have flesh bodies that war against the Spirit, we cannot be 100% sinless.
Once we are glorified and receive our spiritual/glorified bodies, then we can be.
The rest has been drawn out over 7 pages of posts. The idea of sinless perfection is nice, but not scriptural.
This is why we have the sanctification process after we obtain salvation/justification. It's a process for us to conform to Christ that is lifelong and in the process, we allow God to help change us and remove that which is displeasing to Him. During this time, we still cannot be sinless, but as we resist sin and temptation, it's like muscle memory. The more we resist, the stronger we become at resisting sin and temptation.