Martin Luther described a Christian as “simul justus et peccator,” one who is simultaneously just and a sinner.
Firstly, we are not Martin Luther. He tortured himself to rid himself of his sinful tendencies, which were continually harped upon by the Catholic church priests.
We cannot claim such zeal for being holy, so we cannot fathom what sort of 'sinner' he was
In fact, his confessors would eventually complain that Martin would be confessing sins that are of no substance at all, and are not worthy of even confessing.
Again, we are not Martin Luther.
The greatest sins he permitted in himself are things that our conscience wouldnt even consider twice. So, his interpretation of 'sinner' is NOT the same as ours.
Nowadays, we permit adulterers, drunkards, gluttons, thieves, liars, and greedy crooks in our churches and pulpits, which Martin would whip out in a heartbeat.
The worst kind of 'sinner' Martin was is akin to our best of saints nowadays.
The bible clearly makes a polar opposite distinction between sinners and saints. WE CAN NOT BE BOTH AT THE SAME TIME, for Jesus is not a friend of sinners, no matter what your inept preacher tells you:
Heb 7:25-26 NKJV - 25 Therefore Jesus is also able to save to the uttermost those who come to God through Him, since He always lives to make intercession for them. 26 For such a High Priest was fitting for us, [who is] holy, harmless, undefiled, SEPARATE FROM SINNERS, and has become higher than the heavens;