How are Christians suppose to accept homosexuals who say they are believers in Christ Jesus and in all of what God’s Word in the BIble says about their lifestyle, but do not accept the idea that God in whatever person (Father, Son and/or Holy Spirit), if only asked, can change their sexuality?
In the first place you are right that homosexual and lesbian sexual behavior are indeed condemned in the scriptures (see, for instance, Romans 1:26-27). But then so is adultery, theft, and a host of other sins. The Bible does not encourage us to treat homosexual persons with less respect, or as worse sinners, than any other kind of sinner. The old distinction between loving the sinner but not loving the sin is a good one and applies.

We are not called to accept anyone’s sinful lifestyle, be they heterosexual or homosexual. In regard to welcoming people into the church, everyone is welcome to come as they are. But no one is welcome to stay as they are.
Jesus calls all of us–all sinners–to change. The church is supposed to be a hospital for sick sinners, not a museum for saints. The New Testament clearly teaches that whatever one’s sinful inclinations, God’s grace is sufficient to help anyone get beyond temptation and resist sin (see 1 Cor. 10:12-13).
The issue here is not one’s inclinations or temptations but one’s behavior. The New Testament teaches that one’s behavior can be modified with the help of God’s grace. Is God’s grace powerful enough even to change human nature and its fallen orientations? Yes indeed, and there are numerous authentic testimonies of former gay and lesbian persons as well as former liars, thieves, heterosexual sinners, etc. who make this evident.
—Ben Witherington III