Now you are the body of Christ, and each one of you is a part of it.
—1 Corinthians 12:27
On that day you will realize that I am in my Father, and you are in me, and I am in you.
There is the distinction between the ideal of "liberation" in the Buddhadhamma and the ideal of "salvation" in the Christian tradition. Both point to a kind of freedom, but the emphasis is different.
When we speak of liberation, we mean freedom from greed, hate and delusion. It is something to be attained, through skillful kamma. And this highest nibbana is not something that any saviour can win on our behalf.
When we speak of salvation, we mean freedom from the tethers of sin. It is something that cannot be attained, regardless of how skillful our actions might be. It is available only through the grace of God, when our old self literally dies and we are born anew, and described in Romans 6:4 -- "We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life." And this highest salvation is something that only the Saviour can win on our behalf.
The argument sometimes is made that this Christian conception of salvation directly defies the Dhamma understanding of kamma, that is, volitional action that produces consequences. After all, if a sinful man need only repent and "accept Jesus" in order for all his sins to be washed away, where is the effect of kamma to be found?
The question itself is an oversimplification of the Christian understanding of salvation, which is predicated on a deep, complete annihilation of the old self in the rebirth in relationship with Christ. A similar transition can be found in the story of Angulimala, the serial killer whom the Buddha converted. Later, as a venerable monk, Angulimala proclaims: "Since I was born with the noble birth, I have never purposely deprived a living being of life."
The deeper issue raised in this dichotomy between "liberation" attained by oneself and "salvation" bestowed by another is the core delusion of self-identity view, sakkaya-ditthi. Who is doing the saving? The habitual Christian will answer, it is Jesus. The Buddhist, not understanding, might object that the Christian thereby abdicates responsibility for his own kamma and falls short of the requisite right view (samma ditthi) necessary even to take a few steps along the noble path. And the Christian, not understanding, might object that the Buddhist builds himself up as a false God, idolizing his own ability to effect that supreme victory over death.
All of these objections are based on ego, on conceptions of self-identity view. They must be completely set aside to arrive at a deeper understanding of the path of practice. And indeed we find in the Christian tradition it is based once again on selflessnes, as Jesus instructs: "Love the Lord your God with all your heart and with all your soul and with all your mind. This is the first and greatest commandment. And the second is like it: Love your neighbor as yourself." (Matthew 22:37-39)
There is a transformation at work in these practices, a transformation to eradicate the delusion of self and other, to eradicate hatred, to radiate lovingkindness. If the habitual Christian is to make any sense of the Buddhadhamma, it must be recognized that the goals of salvation and liberation are identical: that supreme deathlessness. Then the question of "me," the question of where the line is drawn between self and Christ, simply doesn't arise, because it's not relevant.
"You have been given fullness in Christ." (Colossians 2:10) With this victory, what need be said of the self? Such a concept is unnecessary. And indeed shades of kamma are hidden in plain view in the Christian teachings, such as when we are told: "I tell you the truth, whatever you did for one of the least of these brothers of mine, you did for me." (Matthew 25:40)