Jesus was “the firstborn among many” and “the firstborn of a new creation”. Jesus alone is the “only-begotten” Son by virgin-birth. He was conceived by Mary when the Spirit of God overshadowed her. We are the siblings of Jesus because we were “born again not of corruptible seed but of incorruptible, by the word of God…”
We had to be “born again”spiritually to receive the sinless nature of Jesus, a divine nature that does not sin, and indeed cannot sin. But the old nature can and does prompt us to sin but only when fwe fail to “reckon it dead” through our “burial” in baptism. As often as we do that we do not sin. It’s that simple.
Note that the Apostle John does not write “when” we sin but “if” we sin (1 John 2:1). Sinning is not inevitable. But trying to ‘crucify’ the old self does not work: we must “reckon [count] ourselves as being dead indeed to sin and alive unto God through Jesus Christ.”
In other words, we cannot “crucify” the sinful nature that predisposes us to sin, but must see that nature as having been “crucified with Christ” when Jesus, who knew no sin but was made sin for us”. and the new self beyond water baptism as a “new creation”.
Doing this is not a kind of mystical mantra but a matter of identifying the old, sinful self with Jesus in his death and burial, and the new, sinless self with Jesus in his resurrection. (Romans chapter 6.)
I call it Operation Identification because salvation is not only an event but also a process, a cyclical daily one until sinning becomes a rare thing instead of a daily thing. Thank God for 1 John 1:9, which assures us that when we confess He is “faithful and just to fogive us our sins and to cleanse us from all unrighteousness”. But let’s try our very best to not accept this assurance a daily treadmill.