Against same sex Marriages

Why do Gay people want to get Married ? Why dont they just have a civil partnership ?
Is  this the next step for imposing on the Christian Church the right to get Married

Same sex Marriage is totaly against our Christian belief's, and any Christian, Catholic ect. who condone's it is Guilty of sin, because they are going against the teaching of Jesus Christ. Marriage is a Sacrament from God.

Matthew 19:4-6

"Haven't you read," he replied, "that at the beginning the Creator 'made them male and female,' and said, 'For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh' ? So they are no longer two, but one. Therefore what God has joined together, let man not separate."