“And the curtain of the sanctuary was torn in two from top to bottom.”
~Mark 15:38

Jehovah’s spiritual temple arrangement to replace the physical temple of animal sacrifices began upon Jesus’ anointing during his baptism three and a half years before his death. (Heb. 5:5; 10:5)
At that time, the heavenly “Holy of Holies” was set up for Jesus to later enter and present himself before Jehovah’s throne as high priest. (Da. 9:24; Heb. 6:20; 8:2; 9:24)
But Jesus could not enter in the flesh. (1 Cor. 15:50)
Therefore, the literal curtain being torn illustrates how the barrier holding Jesus back from entering the heavenly Holy of Holies was removed upon the death of his fleshy body.
The removal of that barrier also opened the way for others who were later anointed to be able to enter heaven. (Acts 2:33; Heb. 4:14-16)