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.
Nowhere did I suggest that showing "kindness" wins spiritual salvation. To the contrary, Scripture states clearly that salvation is by grace, through faith alone.
And unless I am misunderstanding what you're saying, then you seem to be the one caught up in some kind of pharisaic, salvation-by-works concept.
To return to this renting-to-gays example; if renting to a sinner makes you complicit in his sin, then I surely hope you are not a landlord. If you are a landlord, then most certainly your rooms are vacant. For nobody is sinless, not even the redeemed.
If renting to a homosexual makes you complicit in his homosexuality, then renting to a thief makes you complicit in his theft, and renting to a liar makes you complicit in his lying, etc.
By your reasoning, a landlord could safely rent his room only to the One, Perfect Man who ever lived. But Jesus ain't shopping around for new digs today. He sits at the right hand of the Father Himself, in Paradise.
Or is the issue that you consider homosexuality to be a worse sin than other sins? I can tell you that God does not see it that way. The carnal man would say, Surely murder is a worse sin than lying. But the truth is, if you lived an otherwise *perfect* life, save only one tiny, little, white lie, you are as assured to go to Hell as Hitler with the blood of millions upon his hands.
Sin separates a man from God. One particular sin does not separate a man from God any more or any less than another sin.