1) Is it wrong to talk to the ones who passed away ? I read somewhere that it goes against God to talk to the dead.
2) Will we meet in heaven again as we knew each other here while we are waiting for judgement?
3) Also it is said that when we marry we become one. Does that mean when one sins the other one does also?
4) Is it possible for the loved ones to still be with us even though we can't see them? I read that spirits can be here but they are imposters of our love ones.
5) What is the difference between a spirit and a soul ?
Thank you so much for taking the time to read my email
I will try to answer your questions, although the Bible is silent on a couple of them. The Bible, for instance, doesn't say whether it is wrong to talk to those who have passed away. Just don't expect an answer. The Law of Moses forbade the Jews from consulting mediums in order to talk to the dead (Deuteronomy 8:10-12). However, just talking to them on your own without expecting it to be a two way conversation is not addressed.
Your questions about knowing each other in heaven and whether it is possible for loved ones to be near us here on earth may be answered by a passage in Luke 16:19-31. In this story, Jesus indicates that the rich man who had died recognized the poor man, even though they were in different places. It further indicates, although it doesn't say it outright, that people go to a waiting area before judgement and can't return to earth in any form. There have been exceptions in the Bible, but they were rare and clearly the exception rather than normal. I am not sure where you read that there are spirits here, but they are impostors of our loved ones. That is not taught in the Bible.
You ask the difference between the spirit and the soul. You can find my answer to that at What Does the Bible Say About the Spirit and the Soul? The simplified answer is that the spirit is the breath of God in us, and the soul is what lives on after the spirit (breath) is no longer in us.
Your other question is an interesting one. If the two become one in marriage, does the sin of one apply to the other as well? First, the scripture says they become "one flesh." (Genesis 2:24) Paul makes a distinction between "one flesh" (joining with harlots) and "one spirit" (joining with God) in 1 Corinthians 6:16-17. A man and a wife become one flesh, but are still two distinct persons with different thoughts, motivations, and even actions. They are two different souls. Therefore, the wife is not guilty of the sins of the husband nor the husband of the wife. "The soul that sins, it shall die." (Ezekiel 18:4) Even though joined together, a wife is not fully responsible for the husband's sins that don't include her, nor he of hers.