Are the 144,000 of Revelation 7 and 14 the same group of people?
The answer is "Yes", Revelation 14 says " These have been purchased from mankind as first fruits to God and to the Lamb.
Revelation 14:4 NASB
4 These are the ones who have not defiled themselves with women, for they are celibate. These are the ones who follow the Lamb wherever He goes. These have been purchased from mankind as first fruits to God and to the Lamb.
In Revelation 7:4-8 the tribes of Ephraim and Dan do not appear as not deserving symbolic significance, the twelve tribes mentioned are symbolic and refer to the spiritual Israel, or the "Israel of God".Literal circumcision, even for fleshly Jews, had no further spiritual value in God's eyes. For those in the new covenant, the heart, not the flesh, must be circumcised. Hence Paul wrote.
Galatians 6:16 NASB
16 And all who will follow this rule, peace and mercy be upon them,
and upon the Israel of God.
Romans 2:29 NASB
29 But he is a Jew who is one inwardly, and circumcision is of the
heart, by the Spirit, not by the letter; and his praise is not from
people, but from God.
The gathering of the 144,000
For seven years,(Daniel 9:27 The Abrahamic covenant)) this unique privilege of "adoption as sons of God was preached" to the Jews, but since not enough of them accepted the invitation, it was also preached to the Gentiles. With Cornelius being the first gentile to be "adopted as a son of God".
Natural Israel failed to produce the required number, so God “turned his attention to the nations to take out of them a people for his name”. From Romans 11:13 we note that Paul is addressing Christians of non--Jewish origin, and continues in Vs 17 with the illustration of the cultivation of an olive tree to show how God’s purpose with regard to the Abrahamic covenant (Genesis 17:1-8 and 22:15-18) was being fulfilled.
Since non-Jews would receive this “holy calling” only until the “full number” was reached of those making up “the Israel of God,” (Galatians 6:15-16) logically the number of such spiritual Israelites purchase from among mankind is limited to 144,000.00
The parable of the Great Banquet." Luke 14:15-24 NET also refers to the calling of the 144,000
https://classic.biblegateway.com/passage/?search=Luke%2014%3A15-24&version=NASB;NET
The Man providing the meal Vs 16 is God, the slave extending the invitation is Jesus Vs 1 7and the invitation to the great banquet, the opportunities to be in line for the Kingdom of the heavens.
First, call. Vs 17-20 To those invited, refers to the Israelite religious leaders.
From Pentecost 33 C.E.the invitation was extended to the ordinary Israelites the poor the needy, and the lowly ones of the Jewish Nation.
The second call, Vs 21 " Then the master of the household was furious and said to his slave, ‘Go out quickly to the streets and alleys of the city, and bring in the poor, the crippled, the blind, and the lame.’
Again , since not enough Israelites responded to the invitation, in 3 6 C.E. three and a half years later the invitation was extended to the people of the Nations, the uncircumcised non-Jews. The gathering is continuing to our days.
Third call. Vs 23 was to the Gentiles ."23 So the master said to his slave, ‘Go out to the highways and country roads and urge people to come in, so that my house will be filled.