“To live is Christ” is the daily, moment by moment, discipline of considering who you really are. You are dead to sin and alive to God in Christ Jesus. This is your new reality. A new glorious reality that we are called to both rest in and walk in.
“To live is Christ” means your sin has already once and for all time been dealt with by the cross. Do you know this? Do you believe this? Once you do, you can start the painful process of crucifying the flesh and its selfish desires by faith in God’s saving grace.