NOTES for Rom 6:8
According to the apostle Paul, our union with Christ takes place not in life, but in death. Because what we call life, from God's point of view, is dying. And Christ, by His divine nature untouched by death, voluntarily enters our dying in order to meet us "on our territory."
This is a self-emptying of the Son of God completely unimaginable for us, "kenosis" in Greek, an enormous path traveled from God to us. But for a meeting to happen, our movement toward Him is also necessary. It happens when we take a very small step, agreeing that Christ did not simply die for no reason, but out of love for us and for our sake; that in our baptism we experience His death as a fact of our own personal biography, radically changing the direction of our movement, because dying ends there. Having met Christ in death in this way, we are not separated from Him in resurrection either.
The word "believe" is very precise here: this is not scientific knowledge, but trust in God, hope in the saving power of His love for us.