When writing to the Romans, Paul speaks of a delicate pastoral situation in the first-century Church. There were many Jewish Christians who still believed that certain foods were unclean or otherwise forbidden (e.g., much of the meat sold in Gentile markets had been sacrificed to idols). Paul explained that none of these foods were really unclean or forbidden, but stressed that his readers should not do things that would tempt people into eating these foods if it would violate their consciences:
Then let us no more pass judgment on one another, but rather decide never to put a stumbling block or hindrance in the way of a brother. I know and am persuaded in the Lord Jesus that nothing is unclean in itself; but it is unclean for anyone who thinks it unclean. If your brother is being injured by what you eat, you are no longer walking in love. Do not let what you eat cause the ruin of one for whom Christ died. (Rom 14:13–15)
The mortal consequences of sinning in this way are clear. Paul speaks of an individual being “destroyed” by violating his conscience in this way: “Do not, for the sake of food, destroy the work of God. Everything is indeed clean, but it is wrong for anyone to make others fall by what he eats” (Rom 14:20). “But he who has doubts is condemned, if he eats, because he does not act from belief [i.e., in accord with his beliefs or conscience]; for whatever does not proceed from belief is sin” (Rom 14:23).
Leviticus Chapter 17 verse 14.
Since the life of all flesh is its blood. I have told the Israelites: You shall not consume the blood of any flesh. Since the life of all flesh is its blood, anyone who consumes it shall be cut off. Lev 17:14
Again, let’s read the text in context. This law was given to the Jewish people and aliens Not Christians yet. Because Jesus our messiah was not sent yet.
You shall eat no blood whatever, whether of fowl or of animal, in any of your dwellings. Whoever eats any blood, that person shall be cut off from his people (Lv 7:26-27).
For the life of every creature is the blood of it; therefore I have said to the people of Israel, You shall not eat the blood of any creature, for the life of every creature is its blood; whoever eats it shall be cut off (Lv 17:14).
• You can say four things. First, any divine command that comes later modifies divine commands that came earlier. When Jesus declared all foods clean (Mk 7:19), his command superseded the earlier command that certain foods be regarded as unclean (Lv 11:1-8). If Jesus today commands us to drink his blood, his command supersedes any prior command concerning drinking blood.
• Second, the command against drinking blood, like all of the Old Testament dietary regulations, has passed away, for "These are only a shadow of what is to come, but the substance belongs to Christ. Therefore let no one pass judgment on you in questions of food and drink" (Col 2:17, 16).
• The mention of not eating blood in Acts 15:20, 29 was a pastoral provision suggested by James to keep Jews from being scandalized by the conduct of Gentile Christians. We know that these pastoral provisions were only temporary. One concerned abstaining from idol meat, yet later Paul says eating idol meat is okay so long as it doesn't scandalize others (Rom 14:1-14, 1 Cor 8:1-13).
• If it is objected that blood is not a food (though it is in some cultures), note that Jesus was asked (Mk 7:5) why his disciples ate with unwashed hands. He replied, "Don't you see that nothing that enters a man from the outside can make him unclean? For it doesn't go into his heart but into his stomach, and then out of his body" (7:18-19). In context this refers to a non-food substance (the dirt on one's unwashed hands).
• Third, the Old Testament is very specific about why one was not to eat blood: "The life of every creature is the blood of it; therefore I have said to the people of Israel, You shall not eat the blood of any creature, for the life of every creature is its blood" (Lv 17:14, cf. Dt 12:23). The Israelites could not eat animal blood because it contained the animal's life, but there is one Person whose life you must have in you, "Christ who is your life" (Col 3:4).
Reference: Catholic.com
