Precisely. God judges the attitude of your heart, your motives.
So if you rent to a gay couple to be kind, God won't condemn you.
If you rent to a gay couple merely to facilitate their having gay sex, then that is something else entirely.
The concept of “kindness” is not in and of itself a source of spiritual salvation where consent is extended to accommodate a sinful objective. Otherwise, even the murderer can bludgeon a victim and hand him a glass of water (as an act of kindness) before the victim dies.
All acts of kindness extended to those who admit to sorrow and repentance of the sin is spiritual. Giving a free ride to a stranded transient is no act of spiritual kindness if he plans to rape his girlfriend (sin) at the point of destination.
Even the Christ demanded this renunciation of sin and restoration to spiritual kindness. Luke 17: 11-19. Jesus told the lepers to go and show themselves to the priest.