Hi Yurt,
I know Adventists who are very nice people, though there are always some bad eggs. They generally love God and keep the seventh day Sabbath, meaning they spend time with God and family on Saturday in keeping with the 4th of the 10 commandments (Ex 20:8). The other part of their names comes from the fact that they live their lives looking forward to the 2nd advent, or coming of Jesus, to take those who truly want to go home with him to heaven (Acts 1:7-12).
Hope that helps! More info can be found on adventist.org