Why should we be hasty about reaching the spiritual goal in this birth?

[The Gita says that one can attain Vaasudeva after several births.]

In that verse the Gita also says that the person attains Vaasudeva. This means that the Lord is referring only to the devotees who can attain Vaasudeva. Vaasudeva means the son of Vasudeva. This represents the the external human body, which will not be present in the future births. Instead of Vaasudeva, some other human form will be present in the next birth. Therefore this verse speaks about the lifetime of Vaasudeva. In that lifetime, a devotee, who recognized Vaasudeva as the Lord was very lucky. A human incarnation speaks like that only during the lifetime of that human incarnation. In that verse the word Vaasudeva has special significance. Other words like Paramatma were not used in that verse. If such words were used the meaning would have been the Lord in general, who pervades all the human incarnations. Shankara says that human rebirth is impossible (Nara Janma Durlabhamidam). Christianity and Islam also say that the human rebirth is impossible. In this verse that concept can be interpreted. Hindus misunderstood the concept and are neglecting the spiritual effort due to the assumption of availability of several future human rebirths.