It is an assignment. At least in the world of Jehovah's Witnesses. Jehovah's Witnesses proclaim that you must deny yourself and dedicate your entire being to Jehovah. This mean not pursuing your own interests.
As a reward for being faithful, you will be spared at Armageddon and live forever as a slave to Jehovah. You will pursue his purposes, forever, and his purposes alone. Living forever as a non-thinking robo-slave.
Also, everlasting life is not immortality. Immortality infers that life comes from within ones self. Where as everlasting life means you will live as long as something unnatural does not cause your death.