"It's sad, really...bullying is unacceptable behaviour but children deciding to be gay is also unacceptable behaviour."
Nobody "chooses" any such thing you jackass.
"The gay lifestyle is a chosen lifestyle."
Fine. I'll tell you the same thing I tell everyone that says this: choose to be gay for 30 minutes. Go on. Find someone of your own sex irresistibly attractive sexually--so much so that you would not only consider having sex with them, you'd actually go through with it.
If you can't do this then you need to shut the fuck up.
"God would not have a baby born gay."
Is your god omniscient or not? If so, then he already fucking knew the person would be gay--by choice or not--and should not have "created" them to begin with. If he's not omniscient, why does your Babble lie to you and say he is (except for those parts where he's clearly not, but you can ignore those like all the other contradictions).
"He opposes homosexuality so, therefore, He would not allow a child to be "born gay". That's totally ridiculous!"
Much like the rest of your half-baked religion.
"If you have a child, pre-teen, or teenager that has chosen to be gay, I feel nothing but sorrow for you. And all I can do is pray that none of my grandchildren, great-grandchildren, great-great grandchildren, etc., choose that lifestyle."