ANSWER: Jesus came into this world to save sinners (I Timothy 1:15; John 1:29). Though “He knew no sin, He was made to be sin for us, that we might be made the righteousness of God in Him” (II Corinthians 5:21). The blood of animals could not take away our sin (Hebrews 10:4), so Christ became the only perfect sacrifice, by which we could be sanctified (Hebrews 10:10-12) through His blood, which was shed for many for the remission of sins (Matthew 26:28).
Because of our sin (which God hates), we deserved the prescribed penalty of death and eternal separation from God (Isaiah 59:1-2). Either we had to pay the penalty for our sins or a perfect, sinless sacrifice had to be found to pay the penalty for us. Paul tells us (Romans 5:8-9) that God demonstrated His love toward us, in that, while we were yet sinners, Christ died for us. Much more then, being now justified by His blood, we shall be saved from wrath through Him.” Christ paid the penalty for you and me in His death (I John 2:2).
Dave Amos, Truth for the World