SACRIFICE means you give up something,or someone for a better cause,or greater good. Most folk will sacrifice their time,money,and whole life for something that will be beneficial for them in the future. But God demonstrates to us what ultimate sacrifice does by giving up His only begotten Son,and His Son demonstrate His love for God His Father and us by sacrificing His life. In Romans 8:32 it says, “He who did not spare His own Son, but delivered Him up for us all, how shall He not with Him also freely give us all things?
Hebrews 9:23-28 NKJV

Therefore it was necessary that the copies of the things in the heavens should be purified with these, but the heavenly things themselves with better sacrifices than these. For Christ has not entered the holy places made with hands, which are copies of the true, but into heaven itself, now to appear in the presence of God for us; not that He should offer Himself often, as the high priest enters the Most Holy Place every year with blood of another— He then would have had to suffer often since the foundation of the world; but now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself. And as it is appointed for men to die once, but after this the judgment, so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation.