Hebrews 13:12 "So Jesus also suffered outside the gate in order to sanctify the people through his own blood."

Paul is comparing Jesus to the animals the Jews were to burn outside the camp, and whose blood the high priest was to bring into the sanctuary as a sin offering for the people. Just as those animals were sacrificed outside the camp, or "outside the gate," so was Jesus.

Inside the gate is the Tabernacle, where where heaven meets earth. We, unfortunately, are born outside the gate, separated from heaven and unable to get back on our own. So, out of love for us and an unwillingness to be separated from us for eternity, Jesus humbled Himself so much as to not only come and live outside the gate, but to be sacrificed there, and His blood drained as a sin offering, gaining us entrance inside the gate.

He not only opened the gate, He also poured His redeeming blood over us (see also "There Will Be Blood"). We can now enter through the gate with the High Priest who is also the Lamb who was slain. This is so deep, mystical, and beautiful!