John 17:17 "Sanctify them by Your truth. Your word is truth."
The word of our Lord Jesus is truth. His blood on the cross ended the old covenant.
Mat 26:28 For this is My blood of the new covenant, which is shed for many for the remission of sins.
Mat 11:13 "For all the prophets and the law prophesied until John."
The feasts and religious, ceremonial and moral laws were all set up during Moses' time in the book of Leviticus. God often sent His prophets to warn the Israelites of their sins and abominations. John the Baptist was the last OT prophet.
{The crucifixion and resurrection of our Lord Jesus fulfilled the religious and ceremonial Laws. The complete destruction of the temple of God later, confirmed the end of Judaism (no more place for priesthood, animal sacrifices and the observations of feasts, religious and ceremonial laws.}
Since John, the kingdom of God was preached by our Lord Jesus, giving us His grace and His words (including His teachings, commandments, etc.), which are truth.
John 1:17 For the law was given through Moses, but grace and truth came through Jesus Christ.
Gal 3:10 For as many as are of the works of the law are under the curse; for it is written, "Cursed is everyone who does not continue in all things which are written in the book of the law, to do them."
Whoever breaks just one law will be under the curse. So please brethren do not keep any law esp. all the feasts, religious and ceremonial laws. Leave it to our Lord Jesus to fulfill the Seventh Month feast, when He will come at Rapture and also for His Millennium Rule.
Jam 2:8 If you really fulfill the royal law according to the Scripture, "You shall love your neighbor as yourself," you do well;
Rom 7:23-25 But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members. O wretched man that I am! Who will deliver me from this body of death? I thank God—through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin.
Until a Christian has truth, he is just like the Jews under the bondage of law. Though he worships God with his mind, his flesh will still serve sin. But once he accepts God's grace by abiding in His words, he will know the truth which will free him by crucifying his flesh (sanctification)
John 8:31-32 Then Jesus said to those Jews who believed Him, "If you abide in My word, you are My disciples indeed. And you shall know the truth, and the truth shall make you free."
1John 5:6 This is He who came by water and blood—Jesus Christ; not only by water, but by water and blood. And it is the Spirit who bears witness, because the Spirit is truth.
All those who rejects the words of Jesus as Spirit, rejects truth, freedom from bondages, heresies, worldliness, deceptions, sins, abominations, etc.
2Cor 3:17 Now the Lord is the Spirit; and where the Spirit of the Lord is, there is liberty.
Rim 1:18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness,
Brethren, repent for not believing, accepting and abiding in the words of Jesus, which is truth, Spirit and life.
Rom 2:8 but to those who are self-seeking and do not obey the truth, but obey unrighteousness—indignation and wrath, tribulation and anguish, on every soul of man who does evil, of the Jew first and also of the Greek;
