And how do they know God loves all his children? Because the Bible says so. They can't pick and choose from the Bible. If they choose to believe the parts that say God loves us, then they also should believe the parts about homosexuality being an abomination and those who practice it being damned.
Not that anyone at that event cares, but we are actually born apart from God, and are referred to as children of Satan,m John 8:31-44. Only those who believe on the name of Jesus are given the right to be called "Sons of God" John 1:12.
People love to claim we should be who God made us to be. However, they forget God only made 1 person, Adam, and only begot 1, Jesus. We were born of our parents, and of the husbands will. We are sinful, because we are born into it, and can only be God's child if we are born again, John 3:3.