I don't understand how you have come to this belief. Why are you not able to accept that once we are saved we still sin?Just one point. I think it is important to understand that Christians don't sin, they fall but get right back up. If one is in Christ you can't sin because the only 'real' sin is unbelief. Jesus said 'go and sin no more' saying keep walking in Me.
It sounds like you are stating the ONLY sin after salvation is UNBELIEF.