Do we who follow Messiah pick and choose the things of God?

We pick Sunday to worship, although most denominations know that the Sabbath has never changed from 6Pm Friday to 6Pm Saturday. Can we find scripture that says Sunday is right? I do not know of any. The Father himself made Sabbath long before He gave the commandment to men. Genesis 2:2; Exodus 20:8,11; Exodus 31:16; Leviticus 23;
We say that Yahushua is our teacher and master yet He always worshipped on the Sabbath and Holy convocations (festivals).
We say we love and reverence Him, yet we do not call Him by His name: Yah (God), Yahuweh (Father), and Yahushua (Yahuweh-saves[Jesus]).
Most do not know or teach that the words Halle la YAH is not one word but three in Hebrew that Praise his name YAH.
Yahuweh asked you to wear a Talite(Prayer shawl),Numbers 15: 39-41; Deuteronomy 22:11,12; Yahushua wore one, Paul, and Peter.
Many denominations do not accept the gifts of the Spirit, teach them or move the body in them. I Corinthians 12 Or only some of the gifts are used. Does this make YAH(God) a liar? Are not all the gifts for today?
Christians believe that Jews have to become more like Christians. We couldn’t be more wrong. A Jew merely has to repent and accept the Messiah has come. Acts 2:38
We as Gentiles have to learn not only the New Covenant, but, the old.
Israel Knows His Name. Israel Honors the Sabbath and the festivals, Israel wears the Talite and understand the ways of Yahuweh.
Romans 3:1 What advantage then hath the Jew? Or what profit is there of circumcision? 2. Much every way: Chiefly, because that unto them were committed the oracles of God. Oracles are the very Word of God.
Do the scriptures lie than, are all the denominations right? Does our religion come from Rome or from God? Do the Jews who have been trusted by God for the Word, lie.
Who wrote the New Covenant: Jews (ISRAEL) or Constantine; Jews (ISRAEL) or Rome? Neither but by the Holy Spirit and given to ISRAEL. The witness to the New Covenant is the Torah and the books of the prophets. Hebrews 6:17-18
Honor the Father, Yahuweh, Glorify the Son Yahushua, pray by the Spirit.

I Corinthians 14:14,15

Does God change? Hebrews 13:8 Yahushua Messiah the same yesterday, and today, and forever.
Romans 10:12 For, there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon Him.
Romans 12:3 For I say, through the grace given unto me, to every man that is among you, not to think of himself more highly than he ought to think; but to think soberly, according as God hath dealt to every man the measure of faith.
Isaiah 51:7 Hearken unto me, ye that know righteousness, the people in whose heart is my law; fear ye not the reproach of men, neither be ye afraid of their revilings.
Read all of the referred to Chapters.