“and be found in him, not having a righteousness of my own that comes from the law, but that which is through faith in Christ–the righteousness that comes from God and is by faith. I want to know Christ and the power of his resurrection and the fellowship of sharing in his sufferings, becoming like him in his death,”
The verses do not indicate a physical suffering. If that is true, then you have die like him on the cross. It speaks an imputation of his death on us. It speaks of his death as our death. Hence to partake in sufferings, we don’t suffer the way he suffers. It means we suffered what he suffered by imputation as well.
How did that happen? The answer lies in the previous verse. Having a righteousness that is not by law but by faith. By believing what Jesus did, he did for me. That is how his death and suffering were imputed on me. That is how I partook in his sufferings. That is how I became like him in his death.
I became one with him in suffering and death by believing he did it for me.
I hope you are blessed.