The essence of GOD of the Bible
The most crucial thing a Muslim must understand in the Christian faith is that GOD Almighty does not hear the prayers of sinners (John 9:31). It’s deeply rooted in the old testament in the time of Moses because GOD did not allow anyone to make a sacrifice to him when Moses was the ruler of the jew. And a prayer wasn’t sufficient because a sacrifice had to be performed according to the sin as it was written in the Torah. Only the sons of Aaron could make sacrifices to GOD for the sins of the people.
They were the chosen tribe among Israel to make sacrifices for the people coming to the temple of GOD. And, once a year, the most holy priest among them had to enter the temple’s holiest place to present the blood of the sheep for the atonement of the sins of all the Israelites. The law of Moses comprises 1) the Ten Commandments, 2) the laws, and 3) the precepts; you must differentiate them. Essentially, nobody had the right to make a sacrifice for himself; only the priest of the tribe of Levi, the ancestor of Aaron. Moses was the king of Israel and at the same time the high priest, Aaron was like his prophet. Exode 7.1-2
Why the sacrifice of Cain wasn’t accepted?
It’s because he sacrificed fruits and herbs thinking it was right. It is pretty much what Muslims do, they think they can pray the way they like but their prayers do not go far.
Before Moses, everyone did whatever they see fit. You need Jesus, you need the Holy Spirit to intercede on your behalf.
GOD Almighty is Holy, you cannot come before him without a high priest. This means that you need an advocate to speak on your behalf because you are not fit to come in His presence.
The Lord said: Yet a time is coming and has now come when the true worshipers will worship the Father in the Spirit and in truth, for they are the kind of worshipers the Father seeks. 24 God is spirit, and his worshipers must worship in the Spirit and in truth.”
25 The woman said, “I know that Messiah” (called Christ) “is coming. When he comes, he will explain everything to us.”
26 Then Jesus declared, “I, the one speaking to you—I am he.”
(John 4, 23)