The portal of eternity opens only in response to the freewill choice of the freewill sons of the God of free will. 5:6.12 | https://mm.spiritualfamily.net/Urantia_Book-Online_Reader-2019/Paper_005.html#5:6.12
Service -- more service, increased service, difficult service, adventurous service, and at last divine and perfect service -- is the goal of time and the destination of space. 28:6.17 | https://mm.spiritualfamily.net/Urantia_Book-Online_Reader-2019/Paper_028.html#28:6.17
The citadel of the spirit. When the flood tides of human adversity... beat about the mortal soul, you may rest in the assurance that there is one inner bastion, the citadel of the spirit, which is absolutely unassailable... 100:2.7 | https://mm.spiritualfamily.net/Urantia_Book-Online_Reader-2019/Paper_100.html#100:2.7