Both the 144,000 and the "Great Crowd") consist of members who are:
144,000 / Great Crowd
a. From every kindred and nation. 5:9 7:9
b. Servants of God. 7:3 7:15
c. Divinely protected thru tribulation 9:4,5 /Acts 14:22 7:14
d. followers of the Lamb 14:4 7:17
e. Redeemed 14:3 7:14
f. Pure and Spotless 14:4 7:13,14
g. Standing before the throne 14:1,3 7:9
h. Before the Lamb 5:8 7:9
i. In His temple (naos) 11:1,2 7:15; 11:19
j. Tenting/residing with God 2Cor.6:16 7:15
i. Dressed in white robes 6:11 7:9
j. Wearing robes that are washed 22:14 7:14
h. A heavenly class 14:1; 4:1,2; 19:1
i. Spirit begotten 7:3 I Jn. 5:1
Note: several of these comparisons were derived from "ISOCF"