The reason we no longer need to sacrifice an animal on a burning altar or present any other sacrifice to God to atone for our sins is because of what Jesus Christ did for us.
Let me explain. God used the sacrifices of the Old Testament to teach His people two important lessons: First, God is absolutely pure and holy, and second, our sins are offensive to Him and make us unrighteous in His sight. How, then, can we be forgiven of our sins and made righteous in the eyes of God? We can't do it by our own efforts; sin still clings to us. The only possibility is if God provides the way -- and He did this by accepting animal sacrifices in place of our own death for our sins.
But Jesus Christ came for one reason: to become the final and complete sacrifice for our sins. When He died on the cross, all our sins were transferred to Him, and He died in our place. No further sacrifice is needed -- because Christ gave His life for us. When we put our faith and trust in Him, the Bible says, "we have been made holy through the sacrifice of the body of Jesus Christ once for all" (Hebrews 10:10).
Have you responded to Christ's sacrifice for your sins? Salvation is a free gift -- free, because Christ has already paid for it by His blood. But like any other gift, it only becomes ours if we reach out in faith and receive it. Why not welcome Him into your life today?