There are 2 ways in which a person comes to the faith, and they need both.

1 is natural reason
2 supernatural reason

natural reason will create sympathy for the faith, and an adherence to the faith based on natural appetites

supernatrual reason will sustain natural reason, and will grow from natural reason, and will provide justification for remaining Catholic in spite of alternatives that also appeal.

Unless they be naturally inclined to agree with traditional values and the faith, they have no love of objective truth, but love instead subjective truth, and they will not change their mind, until some natural cause makes them change their love of subjective truth into the love of objective truth.

In circuмstances where it is not possible to convert someone using natural means, for example by conditioning their psychology to respect objective truths, then it is impossible.

Such people are lost in delirium, and this is a self imposed delirium, and they are damned by choice. Not knowing how to be virtueous, but knowing how to sin, they are lost.

One can preach the message of the gospel, but "he who has ears to hear let him hear", and he who does not, let him be to thee like a heathen and a publican, i.e anathema.

I dont see why Catholics should have to sit down with some faithless one and teach them the basics of objective truth and basic skills in interpreting reality. If they dont have these skills it is because they dont want them, i.e did not find them useful to accomplish their desires.

Hence their desires are evil, and they will get what they deserve.

My question is especially in regards to family members and people you love and care about. What do you do when you clearly see they are spiritually dead and the path of damnation?
........

Pray for them, of course.  People go to Hell because nobody prays for them.  And try to get to Confession every week, or as often as possible.  Know what a snare it is to see people spiritually dead instead of my own spiritual failings.  Make Holy Hours of Reparation on a regular basis. Pray the Litany of the Precious Blood for them.  It gets a little more bearable if we persevere in acts of mercy and mortification.  It's heartbreaking to see those whom we love destroy themselves.  

"Let your light shine before men, that they may see your good works and glorify your Father who is in Heaven."
--St. Matthew 5:16

The above is true especially when you face adversity but project tranquility. It makes the other person think, "What does he have that I don't have?" Then the person's curiosity becomes inquisitiveness. It can be the proverbial spark that turns into a raging inferno.

EDITED TO ADD:
I also agree with soulguard, when he said, "'One can preach the message of the gospel, but "he who has ears to hear let him hear', and he who does not, let him be to thee like a heathen and a publican, i.e anathema.

I dont see why Catholics should have to sit down with some faithless one and teach them the basics of objective truth and basic skills in interpreting reality."

If the person you're trying to reach doesn't want to be reached, it's pointless. I do quite a bit of training in my job, and I always say, "You can't teach someone who already knows everything."

Live and conduct yourself in such a way that draws others to see what animates you, the joy and peace of Our Blessed Lord. Sometimes it is not possible to admonish or give verbal testimony to family. Our Lord was not welcome in His own town.

This doesn't work. There's too many other things for people to be distracted than to see another having joy and peace desire it.