This difference is explained in the passage well known to most believers as well as non-believers. I’ve enclosed the passage at the end of this post. It describes the wandering younger son coming home to his father after eating garbage with pigs in a “far country.”
Relationship is permanent; once a son always a son; once a wife always a wife. These are covenant relationships, one by birth and blood, the other by sworn covenant. That is why broken family relationships are so hard to bear. But they are not broken relationships, they are broken fellowships.
The younger son who was eating with pigs, was still his son. The relationship was there but he was far away, so there was no fellowship.
Fellowship means you have contact with each other. Today that is easy if you have a phone – and who doesn’t? You can have fellowship with many people. You can also NOT answer that phone, NOT text and the fellowship is cut off.
Fellowship is stopped by opinions and choices – I do not choose to go to a certain church, or watch some kinds of movies, or TV. I have a new group of friends, for good or il, and find myself not seeing others that I have known in the past. Changed fellowships are not necessarily bad; they may be required by altered conditions. I have no fellowship with my half-sister but there is no reason to either. We are many miles away and have different friends and interests.
The course of your life will always be affected by your choices of your friends and associates. I had a friend who quit his job because his boss insisted or drinking parties after work. Good for him.
Now here is the passage: Luke 15 , The Parable of the Lost Son
11 Jesus continued: “There was a man who had two sons. 12 The younger one said to his father, ‘Father, give me my share of the estate.’ So he divided his property between them.
13 “Not long after that, the younger son got together all he had, set off for a distant country and there squandered his wealth in wild living. 14 After he had spent everything, there was a severe famine in that whole country, and he began to be in need. 15 So he went and hired himself out to a citizen of that country, who sent him to his fields to feed pigs. 16 He longed to fill his stomach with the pods that the pigs were eating, but no one gave him anything.
17 “When he came to his senses, he said, ‘How many of my father’s hired servants have food to spare, and here I am starving to death! 18 I will set out and go back to my father and say to him: Father, I have sinned against heaven and against you. 19 I am no longer worthy to be called your son; make me like one of your hired servants.’ 20 So he got up and went to his father.
“But while he was still a long way off, his father saw him and was filled with compassion for him; he ran to his son, threw his arms around him and kissed him.
21 “The son said to him, ‘Father, I have sinned against heaven and against you. I am no longer worthy to be called your son.’
22 “But the father said to his servants, ‘Quick! Bring the best robe and put it on him. Put a ring on his finger and sandals on his feet. 23 Bring the fattened calf and kill it. Let’s have a feast and celebrate. 24 For this son of mine was dead and is alive again; he was lost and is found.’ So they began to celebrate.
25 “Meanwhile, the older son was in the field. When he came near the house, he heard music and dancing. 26 So he called one of the servants and asked him what was going on. 27 ‘Your brother has come,’ he replied, ‘and your father has killed the fattened calf because he has him back safe and sound.’
28 “The older brother became angry and refused to go in. So his father went out and pleaded with him. 29 But he answered his father, ‘Look! All these years I’ve been slaving for you and never disobeyed your orders. Yet you never gave me even a young goat so I could celebrate with my friends. 30 But when this son of yours who has squandered your property with prostitutes comes home, you kill the fattened calf for him!’
31 “‘My son,’ the father said, ‘you are always with me, and everything I have is yours. 32 But we had to celebrate and be glad, because this brother of yours was dead and is alive again; he was lost and is found.’”
If the reference to an eternal wife needs explanation I urge you to search for other posts on marriage. This issue is full of complications.