Is pre-marital sex and gluttony a sin, punishable to go to Hell?

Assuming you believe in God, If so, why do most people have no problem doing these sins, make fun of others who are still virgins, and condemn people based on their sexuality. Doesn't the bible say you go to hell for having pre-marital sex? Why do so many people over look this and target other groups for their apparent sins? Also isn't gluttony one of the seven deadly sins, why don't people target overweight people for being sinners.