On this point we agree... that is until a person reaches that "face to face" vision [if he ever does].
As long as we are in this flesh we see darkly, even if we vary in degrees from each other.
Why did you have to add your own bias here with regard to the JWs, Mormons and Catholics? Did your own vision improve in regard to them from the darkened to the face to face? I have had very close association with the 1st and the 3rd types and generalizations won't work with them. I suspect the same would be true of the 2nd. Even if a person is in an ultimately wrong place, according to his own mind it may be the right place for him at the moment. If it really is wrong and his heart is open and seeking, will not God help him come out...?
I used to love to invite the young Mormon missionaries in to discuss the things of God. Some of them were as sincere, or even more sincere, as any of those I have met in more acceptable [to non-Mormon Christians] in the mainstreams of Christianity [what men general identity as Christianity]. I never tried to talk them out of anything. I simply let them know where I was and let them speak for themselves as to where they were or they wanted to be. The JWs were less open, I would guess in part because they were usually older people.
The Catholics were where I grew up. My friends were Catholics and so was I all through my high school graduation. many of them were very good people. Some of them knew God.
"For other foundation can no man lay than that is laid, which is Jesus Christ.
Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble;
Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is.
If any man's work abide which he hath built thereupon, he shall receive a reward.
If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire." I Cor 3:11-15
If we have that foundation to the end we will make it, but as you know people disagree, sometimes sharply, on the details.