Jesus himself made the Sabbath day for man

GENESIS 2:1-3
1 Thus the heavens and the earth were finished, and all the host of them.
2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made.
3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made.

MARK 2:27-28 (Jesus)
27 And he said to them, The Sabbath was made for man, and not man for the Sabbath:
28 Therefore the Son of man is Lord also of the Sabbath.

JOHN 1:1-3
1 In the beginning was the Word, and the Word was with God, and the Word was God.
2 The same was in the beginning with God.
3 All things were made by him, and without him was not anything made that was made.

COLOSSIANS 1:15-16 (Paul about Jesus)
15 Who is the image of the invisible God, the firstborn of every creature;
16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they are thrones, or dominions, or principalities, or powers; all things were created by him, and for him.

Note: Jesus did not say that the Sabbath was made for the Jews, he said it was made for man (Mark 2:27). The Greek words translated "man" in this scripture is o anqrwpoj (Gtr. ho anthropos). Look at some definitions of it:

(James Strong p26) "444. anqrwpoj (559x) anthropos ... man-faced i.e. a human being: man (552x), not tr (4x), misc. (3x).
Anthropos is used (1) generally of a human being, male or female, without reference to sex or nationality:"
(Joseph H. Thayer p46) "444. anqrwpoj -ou, o, [perh. fr. anhr and wy, i.e. man's face; ...] It is used 1. univ., with ref. to the genus or nature, without distinction of sex, a human being, whether male or female: Jn xvi 21. And in this sense a. with the article, generally, so as to include all human individuals: ..."

Look at some examples of where Jesus used this word, with the definite article elsewhere:

(Matthew 5:18) "Let your light so shine before men, ..."
(Matthew 6:1) "Take heed that you do not your alms before men, to be seen of them."
(Matthew 19:10) "If the case of the man is with his wife that it is not good to marry."
(Luke 4:4) "It is written, That man shall not live by bread alone, but by every word that proceeds out of the mouth of God."

As you can see, "ho anthropos" is sometimes used of an individual, but mostly of mankind in General. Could any of these scriptures (or any of the many others) mean only Jews? If not, then it doesn't mean Jews in Mark 2:27 either. Jesus could have used the word for Jew if he had meant only Jews. When Israel left Egypt a mixed multitude also went with them (Exodus 12:38), and even under the Old Covenant these Gentiles had to keep the Sabbath day:

(Exodus 12:49) "One law shall be to him who is home-born, and to the foreigner who sojourns among you."
(Exodus 20:10) "But the seventh day is the Sabbath of the LORD your God; in it you shall not do any work, you, nor your son, nor your daughter, your manservant, nor your maidservant, nor your cattle, nor your foreigner who is within your gates:
(Exodus 23:12) "Six days you shall do your work, and on the seventh day you shall rest; that your ox and your ass may rest, and the son of your handmaid, and the foreigner, may be refreshed."
(Leviticus 24:22) "You shall have one manner of law, as well as for the foreigner, as for one of your own country: for I am the Lord your God."
(Deuteronomy 5:14) "but the seventh day is the Sabbath of the Lord your God: in it you shall not do any work, you ... nor your foreigner who is within your gates; ..."
(Isaiah 56:6-7) "Also the sons of the foreigner, who join themselves to the LORD, to serve him, and to love the name of the LORD, to be his servants, every one who keeps the Sabbath from polluting it, and takes hold of my covenant;
Even them will I bring to my holy mountain, and make them joyful in my house of prayer: their burnt offerings and their sacrifices shall be accepted upon my altar; for my house shall be called an house of prayer for all people."

The word foreigner in all these scriptures refer to someone who was not an Israelite. The Sabbath is never referred to as "the Jewish Sabbath" in the scripture. From the beginning God knew that man would need physical rest, and he provided a day for it. People who ignore this, and work seven days a week, will probably suffer stress, fatigue of some sort, or even ill health. This will not change as long as people are involved in secular work; so as long as it applies, why not set aside the specific day that God ordained and Jesus made? Jesus is the Word of God (John 1:1 with 1:14; Revelation 19:13), he created the Sabbath (John 1:3; Colossians 1:16) for man (Mark 2:27), he was Lord of it (Mark 2:28), and yet Jesus kept it himself perfectly when he was in the flesh (See below). He is the head of the true church of God (Ephesians 5:23; Colossians 1:18), and he has not changed (Hebrews 13:8; 1 Peter 1:25), so if he made it for us, then we need it, and should keep it.