Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace; ~ Ephesians 2:15
Most who are not Christians, and possibly others who are new to Christianity do not understand why the rules and commands of the Old Testament are no longer followed or enforced. Back in the summer of 2016 someone on Facebook asked me;
Why is it now alright to eat shellfish and to not stone adulterers? I gave the following short answer that I hope will be of help to someone here.
I suppose for you the fact of Jesus dying on the cross does not explain much since you do not understand the basic concepts of Christianity, nor are you expected to if you have not been born again. You are not alone and there are many who have been born again that have never given any thought to the subject.
The stoning and killing of adulterers is now forbidden in hopes that they will hear the Gospel, believe and be born again before they die. This is the Mercy and Grace of God brought about by the death of Jesus Christ. Just as we are told in Jesus' parable found in Matthew 13, both the saved and the unsaved are now allowed to exist together in the world, and the Lord Himself will separate them in the end of time. This will be the great day of His judgment.
Regarding shellfish, pork, and everything else once forbidden under the Levitical law, those things have now been cleansed by that same Blood Christ shed on the cross. Acts 10 tells us how God told Peter to not call
unclean that which He (God) has cleansed. This is another example of the mercy and grace of God that this world lives under today. Therefore we have liberty in Christ. This liberty does not free us to willfully sin as some seem to believe, but liberty to be free of ordinances and rituals, such as animal sacrifice for one. In this liberty we are allowed to live our lives as we choose and will either be rewarded or suffer depending on what we do with that life. Basically, this liberty is an opportunity to come to believe in and to know Christ and to surrender our all to Him that we may be born again and live according to His desires for us. Therefore;
Let us hear the conclusion of the whole matter: Fear God, and keep his commandments: for this is the whole duty of man. ~ Ecclesiastes 12:13