If AIDS is God's judgement against homosexuals, doesn't befriending them interfere with his will? 

This is really two questions. First, is AIDS God's judgment against homosexuals? This important question requires a long answer to be satisfying. So, an excellent, challenging book that addresses this question is The AIDS Epidemic: Balancing Compassion and Justice by Drs. Glenn Wood and John Dietrich (Multnomah Press, 1990).

In brief, AIDS is better seen as a reaping of consequences than as God's wrath on a specific group. Ultimately, all death is a result of sin, whether sin inherited from Adam, or personal sin. Certain behaviors (such as sexual intercourse and sharing intravenous drug equipment) carry the risk of infection with HIV. Some engaging in these activities do not contract HIV. Yet others who do not engage in these activities--such as hemophiliacs and infants born to mothers with HIV--sometimes do contract HIV. You simply cannot find Scripture to support HIV/AIDS being God's specific judgment on homosexuals.

Second, is it interfering? Even if God levies a specific judgment, such as when He decided to destroy Nineveh, the Lord always seems to provide someone (like Jonah) to bring a message of hope through repentance. Or like Noah to all those alive at his time. In the first case, the people of the city were saved; in the second, none outside Noah's immediate family.

Whatever you decide about the question of whether AIDS is God's judgment, couldn't you be that messenger of good news? Some may reject it, but others will not. Many men and women with AIDS have turned to Jesus Christ as their Savior in the last years, months, or hours of their life. As the Scriptures say: "Be merciful to those who doubt; snatch others from the fire and save them; to others show mercy, mixed with fear—hating even the clothing stained by corrupted flesh" (Jude 22–23).