Homosexuality is a a condition of disordered sexuality that reflects the brokennes of our sinful world. Persons of same-sex attraction should not be denied community acceptance solely because of their sexual orientation and should be wholeheartedly received by the church and given loving support and encouragement. Christian homosexuals, like all Christians, are called to discipleship, holy obedience, and the use of their gifts in the cause of the kingdom. Opportunities to serve within the offices [elders and deacons] and the life of the congregation should be afforded to them as to heterosexual Christians.
Homosexualism (that is, explicit homosexual practice), however, is incompatible with obedience to the will of God as revealed in Scripture. The church affirms that it must exercise the same compassion for homosexuals in their sins as it exercises for all other sinners. The church should do everything in its power to help persons with homosexual orientation and give them support toward healing and wholeness.
Like many church bodies, they get it mostly right. Homosexuality is a "disorder"--not so much in the sense of a disease (though it may have valid biological associations), but in the sense that in "the brokenness of our sinful world," people have cast God and his truth out of the center. (I love John Piper's analogy that just as the planets' orbits are held in line by the massive gravitational field of the sun at it center, so too do our lives only work rightly when the weight of the glory of Christ is at the center.) The CRC is right in affirming that "Christian homosexuals, like all Christians, are called to discipleship, holy obedience, and the use of their gifts in the kingdom" and that engagement in homosexual practices is against God's will. It's also 100% true that just because someone has struggled with same-sex attraction--perhaps even a lifelong struggle--that they can still be genuine believers and should be welcomed into the fellowship of the church (Gal. 3:28; Isa. 56:3-5).
The real problem is this: The CRC, like many others I'm sure, defines homosexuality as "a condition of personal identity" (see URL above). Though they define a homosexual as "a personal who has erotic attractiosn for members of the same sex and who may or may not engage in homosexualism," the problem exists in the church when people are viewed as "Christian homosexuals" instead of as "homosexual Christians." The issue is one of nature and identity, and it's not just a battle over semantics.
Saint Paul explained to the Galatians that "you are all sons of God, through faith. For as many of you as were baptized into Christ have put on Christ. There is neighter Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus" (Gal. 3:26-28). Similarly he proclaimed to the Colossian church, "Here there is not Greek and Jew, circumcised and uncircumcised, barbarian, Scythian, slave, free; but Christ is all, and in all" (Col. 3:11). "For you have died, and your life is hidden with Christ in God. When Christ who is your life appears, then you also will appear with him in glory" (Col. 3:3-4). It's true that faith in Jesus is what defines and unites believers, not sexual orientation. We're all broken, guilty sinners of one ilk or another, justly deserving God's wrath--but instead receiving his mercy and love through the cross of Christ.
But this is precisely where the CRC's logic breaks down. There is no such thing as a "Christian homosexual." This makes "Christian" and adjective describin the noun "homosexual." Thus being a homosexual is what defines a person; it's who they are. But for all of us baptized into Christ, we must acknowledge that "Christ is all, and in all," and that "Christ ... is your life." Our old identities and defining standards according to the world--even according to our own eyes--are dead and buried. We have died with on the cross, and Christ is now our life, our identity, our core being. Christ is in us and we are in him. "I have been crucified with Christ," Paul testified elsewhere. "It is no longer I who live, but Christ lives in me" (Gal. 2:20). New creatures in Christ are not homosexuals, and they should not view themselves that way. Yes, our perceptions, how we see ourselves and the world, are very strong. They die hard. But God's Word teaches that they all must go. Paul thus wrote off all he once was and cherished (Phil. 3:3-10). He knew that in fellowship with Jesus, the old way of evaluating ourselves and others from an external, worldly perspective had to be discarded (2 Cor. 5:16-17).
So what this means is that for humans made in the image of God, especially those united to Christ by faith, "homosexual" is an adjective, not an identity. When I was in high school and college, being a cyclist was pretty much my identity. Heck, I even shaved my legs as a badge of my commitment to the sport! (It does feel pretty cool when you slide on a pair of pants.) But I was wrong. Yes, homosexual feelings may be all someone knows, but it's not who he is. In the same way, no Christian is an alcoholic or a sex addict or a compulsive liar or whatever. There are lying Christians, alcoholic Christians, and sexually addicted Christians. But it's not the final word on their lives. If it is, then this is what's true of them: "Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor theives, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God" (1 Cor. 6:9-10; cf. Rev. 21:8). For such people, their sins are their very identity, something that cannot be given up in a life of discipleship to Jesus in submission to his Spirit's renewing work. But for others, Paul can continue with the good news, "And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God" (1 Cor. 6:11). God takes sinners, even "the sexually immoral" and "men who practice homosexuality," and gives them a new name, the name of the Lord Jesus Christ, in whom their lives are irreovocably hidden, with grace-abounding glory to come.