The Merriam-Webster dictionary defines "religion" as "the belief in a god or in a group of gods, an organized system of beliefs, ceremonies, and rules used to worship a god or a group of gods." In our anti-supernatural culture this often gets extended to mean any belief system that goes against evidence, as in "believing what you know ain't so."
The same dictionary defines "relationship" as "the way in which two or more people, groups, countries, etc., talk to, behave toward, and deal with each other; a romantic or sexual friendship between two people; [or] the way in which two or more people or things are connected." When I hear somebody say "I'm in a relationship" (like in a movie) they always exactly mean the second of these, the romantic/sexual thing.
The word "relationship" is not in most Bible translations. According to Merriam-Webster, there are no known uses before 1741, which is 130 years after the King James Bible was published. It would appear that modern translations avoid the word because the translators know that it is understood differently by their constituency (see my essay "What Is a Relationship?") than by the general public.
The word "religion" is defined in the Bible as a class of behavior, which God apparently encourages in believers.
Obviously the line "relationship, not a religion" does not appear in the Bible as such, because the word "relationship" is not in the Bible, and also because God does not deprecate religion, neither as defined in the Bible, nor as defined in the dictionary. But the line has a nice alliterative ring to it, so preachers have been repeating it (without definition nor support) for as long as I can remember.
My friend repeated the "relationship" thing to me a few years ago, and when I challenged him, he tried valiantly to defend it based on the dictionary sense of "connection." Everything is connected, so of course there are connections in the Bible. But connectivity not what the Bible teaches, as I show elsewhere.
I asked the pastor I most recently heard the line from, where he found it in the Bible. He'd obviously given it some thought (or maybe the Bible College prof he heard it from did), so he cited John 1:12,13 then went on to explain that "The closest of relationships that we can have is that of Father and Son," which is patently false -- the Bible itself establishes the sexual relationship as much closer [Matt.19:5, 1Co.6:16]. He also carefully defined "religion" to be what people do to reach God, so as to distinguish Christian faith (being "not of the will of man, but of God" [John 1:13]) from it. I pointed out that every religion (including atheism) teaches that their religion is true and all others are human fabrications, so that this does not actually distinguish the Christian belief system from the others (as accepted by their own adherents), and he agreed.
The father-children connection in verse 12 is quite clever as an example of "relationship" in the Bible, except that it's not what that verse teaches. I don't think anybody other than modern Americans is likely to see it that way, so the Bible does not make any effort to explain the significance of "sonship". The American Kool-Aid that every impressionable child drinks in grade school is "that all men [now persons] are created [now evolved] equal." Everywhere else, and in all other times throughout history -- particularly in the Bible -- some people are born with priviledges, and some are not. It's true here in the USA too, but we prefer not to believe it. That's what I call "the American Kool-Aid" which poisons our minds.
Sonship is about rights. "If sons, then heirs," the great Apostle repeated at least twice (two different epistles [Rom.8:17, Gal.4:7]), and the theme also begins the Epistle to the Hebrews. I know of no Scripture that attaches any other significance to sonship than the rights to inheritance. The Prodigal Son takes and squanders his inheritance; when rehearsing his return speech, he admits that he has wasted his right to be a son (the inheritance) and seeks only to return as a servant. The father accepts him back as a son, but there is nothing about affection in this story (as we might expect, if it were a sentimental thing the father does), only that the older son resents the acceptance. His inheritance is being diluted. But Jesus didn't say that. He didn't need to in that culture.
Several times somebody addressed Jesus as "Son of David," but Jesus never explicitly used the title on himself. Obviously there can be no emotional closeness across some 1070 years the way this pastor seems to view the "Father-Son relationship" of John 1:12, so I ask myself, what does the term mean in these contexts? Those who used it clearly wanted and expected Jesus to do something miraculous, they saw the title as granting Jesus the authority (rights) of the Messiah. And he did! On another occasion Jesus gave the Pharisees a riddle on the same title [Mt.22:45, based on Ps.110:1] which makes no sense at all as a puzzle apart from the transfer of rights through history from father to son.
The parable of the tenants likewise makes no sense if you see sonship as sentimentality, the warm fuzzies a father might have for his son. Killing the son in that context only makes the father angry (it did that), but killing the legal heir gives them the opportunity to exercise squatter's rights because the father cannot choose a different heir. That makes sense, while the tenants would never consider so foolish an action if the father's emotions were the only or dominant consequence of sonship -- indeed there are more effective ways to achieve a legal transfer of ownership in modern USA (where inheritance is voluntary, not imposed by law as a consequence of sonship), as anyone who has watched more than a couple thriller movies or "24" episodes knows. Jesus told the story as if the tenants were greedy and wicked but not stupid.
I did not take the time to search the whole Bible for the consequences and implications of sonship, but I did ask this pastor if he knew of anything that gave prominence to the emotional aspect of sonship over the matter of rights. He seemed to think so, but could not give me any references right off. The last time I asked an honest pastor for the Scriptural basis of something he taught but I could not find in the Bible, he also said he'd get back to me. Six months later I reminded him, and he replied that he'd already answered that question. It wasn't really a lie, his actual answer was the empty set, zip, nada, and he did indeed give me that information (by not answering). We shall see if this case is any different. [14 Nov.8: Still no answer, so I guess not]
First Draft: 2014 May 1