The Jewish temple, as described in the Old Testament had 3 sections. 

The (1) outer courts where the general crowd would gather to worship, the (2) inner courts where only the Jews specifically would be allowed in, and finally the area called the (3) Holy of Holies (separated by a curtain to the inner courts).

Inside the Holy of Holies was the Ark of the Covenant, and only the High Priest could enter after he had performed a ton of cleansing rituals.  This was done once a year to make an atonement for the people of Israel before the presence of God. 

When the gospel records the curtain being torn after Jesus’ crucifixion, it resembled that access was now open for all to enter into the Holy of Holies so that everyone could experience God’s presence.

The blood of Jesus sanctifies all who put their trust in Him, and in the eyes of God, we are spotless and blameless.

We are now all invited into the presence of God by believing in His Son Jesus.

Hebrews 4:14-16 (NJKV)

14. Seeing then that we have a great High Priest who has passed through the heavens, Jesus the Son of God,  let us hold fast our confession. 

15. For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin. 

16 Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need.