Some Zen teachers in the West downplay or deny the doctrine of rebirth, but I don't see how one is able to save all beings without rebirth. How can we vow to save all beings if our life ends with this present life?
It's being reborn over countless lives which allows us to save all beings, as far as I know. I wonder if there are Bodhisattvas walking the earth today who were Zen masters in a past life.
Another thing that's emphasized in most Zen sects today is sudden enlightenment, which seems contradictory to progressing through Bodhisattva stages over many lifetimes.
Sudden enlightenment and the Bodhisattva ideal, however, are not contradictory if sudden enlightenment is followed by gradual cultivation:
Guifeng Zongmi, fifth-generation successor to Shenhui, also softened the edge between sudden and gradual. In his analysis, sudden awakening points to seeing into one's true nature, but is to be followed by a gradual cultivation to attain buddhahood.
This is also the standpoint of the contemporary Sanbo Kyodan, according to whom kensho is at the start of the path to full enlightenment.
This gradual cultivation is also recognized by Dongshan Liangjie, who described the Five Ranks of enlightenment]].[web 3] Other example of depiction of stages on the path are the Ten Bulls, which detail the steps on the Path, The Three Mysterious Gates of Linji, and the Four Ways of Knowing of Hakuin Ekaku. This gradual cultivation is described by Chan Master Sheng Yen as follows:
Ch'an expressions refer to enlightenment as "seeing your self-nature". But even this is not enough. After seeing your self-nature, you need to deepen your experience even further and bring it into maturation. You should have enlightenment experience again and again and support them with continuous practice. Even though Ch'an says that at the time of enlightenment, your outlook is the same as of the Buddha, you are not yet a full Buddha.