Q. Do you believe a person may not be saved who does not observe all the seven feasts of the Lord and observes Christmas and Easter?
Salvation has nothing to doing with any type of works. I believe salvation is by faith alone and that righteousness is imparted through faith. But faith and works need to go together. Or a better way of stating it is: “that we need to have corresponding actions working with our faith, or otherwise our faith is dead.” Righteousness comes through faith and holiness comes through obedience. Without holiness, no man will see the Lord. Now to observances. Observing YHVH's Feasts are the duty of every believer. Take Passover (for example), 1 Cor. 11:23-31 speaks of partaking of the Passover (remember, that "Communion" is a man-made doctrine that was handed down to us from the Catholic church). Look at verse 26, we are commanded to observe the Passover (specifying certain portions of the Seder meal)- showing the Lord’s death until he comes. In the book of Acts, we see Shaul (Paul) either going to or from Jerusalem because he observed the Feasts. We see a reference in Acts 27:9 to "The Fast" which is Yom Kippur in which Paul didn’t travel until after Yom Kippur due to weather conditions. In Acts 27, Paul is approaching the end of his life—still observing the Feasts.
Q. If a person takes December 25th to celebrate that Yeshua was born, does God see that as Sun god worship? Similarly, if a person celebrates the resurrection of Yeshua on Easter does God see that as Ishtar worship?
Yes, absolutely. They are pagan practices. Now concerning Xmas and Easter, what does Deut 12:31 say? The summation is that we are not to take pagan practices and do them unto YHVH—they are an abomination! What has the Christian church done? Exactly what the scriptures say not to do. This is part of the “hand-me-down” lies past on to us through our fathers in the faith...Jeremiah 16:19 says;
O יהוה, my strength and my stronghold and my refuge, in the day of distress the gentiles shall come to You from the ends of the earth and say, "Our fathers have inherited only lies, falsehood, futility, and there is no value in them."
Another example is the golden calf. If you look at your Hebrew concordance, the Israelites say this [the calf] is YHVH who brought us up out of the land of Egypt. They gave YHVH the glory, but they attributed His great Name to the calf. 1 Kings 12:32 speak of some of the sins of Jeroboam—one of them was the changing of the appointed Feast days! To continue to celebrate the Christ-mass and Easter are abominations even if someone is ignorant, they are still guilty of trespass. We know ignorance is not an excuse. If you been in the Christian church awhile, many of these Babylonian practices are continued—We need to: “Come out of her My people”.
Q. Since Yeshua is the fulfillment of the feasts, why continue the rehearsals?
Heb 10:25 speaks about: “…not forsaking the assembling of ourselves together…”
The word assembling relates to the sacred assemblies or holy convocations, which is another way of saying the ‘Feasts”- not weekly Sunday gatherings. We continue the rehearsals looking back on the Spring Feasts fulfillment (Passover, First Fruits and Pentecost). We continue to rehearse for the Fall Feasts (Trumpets, Atonement and Tabernacles) because Yeshua hasn’t fulfilled them yet. He will fulfill them when He returns. Also, [after Yeshua returns] the nations will be required to celebrate the Feast of Tabernacles or face no rain (Zechariah 14:16-17). Remember, YHVH said these are My Feasts—not the feast of the Jews. (Lev 23) These are also eternal ordinances (Lev 23). We have been grafted into the House of Israel by Yeshua (Romans 11). It takes a while to understand what it is to be a holy people. I have struggled, because I was never taught them either, but grew up in the western church thinking.
Be blessed!