I understand that speaking in terms of numbers makes it easier to draw distinctions of spiritual maturity for the purpose of answering the question of this thread, but I'm not really a fan of quantifying spiritual maturity just because I think it's oversimplifying things a little bit. As Grace said, there are going to be differing opinions across the board on what the qualifications are for being a "10."
I would agree that being unequally yoked doesn't just apply to dating non-believers but also to those who are at a different place in terms of spiritual maturity. I tend to think of spiritual maturity more in terms of spiritual health, though. You can only be in a relationship with someone to the degree that they are healthy. If someone is unhealthy physically, mentally, emotionally, spiritually, etc., the relationship is going to run into some major problems.
I actually believe that a baby Christian and a long-time Christian can come together and have a godly, Christ-centered relationship if both are spiritually healthy. These are some signs of spiritual health to me:
Is this person taking the necessary steps to kill sin in their life? So instead of being concerned about Person A being brought down by Person B's inexperience in defeating the flesh, is Person B just as passionate as Person A about honoring the other and honoring God through purity and boundaries in the relationship? That is a total possibility.
Is this person pursuing an everyday, ongoing relationship with God? Those of us who have been Christians for a long time can say that there are times when we lose that zeal for pursuing God that we so often see in younger believers. I could see a scenario take place where Person B, who is new to the faith, actually ignites a fire in Person A to study the Word more while over time Person A is the one who helps keep Person B sustained in that discipline after the honeymoon phase wears off.
Does this person desire to grow in his/her faith and conduct the relationship in the context of Christian community and accountability? This kind of goes back to the desire for purity a bit, but way beyond that is the value for Christian community that every Christian should have. There are lots of young believers out there who attend church faithfully and value community.
Does this person confess their sin and failures regularly and trust in Christ's work on the cross for them to cover that sin?
This might be the biggest one of all. It indicates that the person takes their sin seriously, but isn't going to allow sin and failure to discourage them to keep moving forward in holiness, and I would not put it past a new believer to have these qualities.
So to sum that all up, does Person B, the new believer...
...looking to kill sin in his/her life?
...pursuing a daily walk with God?
...pursuing Christian community and accountability?
...confessing sin regularly and trusting in Jesus' work on the cross for his/her salvation?
Other things could be added to this list, but my main point is that spiritual health and maturity isn't necessarily so much contingent on how long the person has been a Christian as it is how great their desire is to live biblically. I could see all of these things being true of a baby Christian, maybe even moreso than the more mature believer in some respects. So as we're looking for potential lifemates, I think we should be more concerned with a person's hunger and yearning for God and for righteousness than we should be about whether or not they swear. The swearing will go away over time as they grow, but the growth can only happen if the hunger for it is there.
Side note: These should all be things we desire and encourage young believers that we know towards as we walk alongside them, and these should be things we have incorporated into our own lives as well--believing the gospel, killing and confessing sin, being in community, being accountable, studying the Bible and praying. It's easy to slack in all of these areas because the reality is that none of us will ever be a 10 on this side of heaven.
I would agree that being unequally yoked doesn't just apply to dating non-believers but also to those who are at a different place in terms of spiritual maturity. I tend to think of spiritual maturity more in terms of spiritual health, though. You can only be in a relationship with someone to the degree that they are healthy. If someone is unhealthy physically, mentally, emotionally, spiritually, etc., the relationship is going to run into some major problems.
I actually believe that a baby Christian and a long-time Christian can come together and have a godly, Christ-centered relationship if both are spiritually healthy. These are some signs of spiritual health to me:
Is this person taking the necessary steps to kill sin in their life? So instead of being concerned about Person A being brought down by Person B's inexperience in defeating the flesh, is Person B just as passionate as Person A about honoring the other and honoring God through purity and boundaries in the relationship? That is a total possibility.
Is this person pursuing an everyday, ongoing relationship with God? Those of us who have been Christians for a long time can say that there are times when we lose that zeal for pursuing God that we so often see in younger believers. I could see a scenario take place where Person B, who is new to the faith, actually ignites a fire in Person A to study the Word more while over time Person A is the one who helps keep Person B sustained in that discipline after the honeymoon phase wears off.
Does this person desire to grow in his/her faith and conduct the relationship in the context of Christian community and accountability? This kind of goes back to the desire for purity a bit, but way beyond that is the value for Christian community that every Christian should have. There are lots of young believers out there who attend church faithfully and value community.
Does this person confess their sin and failures regularly and trust in Christ's work on the cross for them to cover that sin?
This might be the biggest one of all. It indicates that the person takes their sin seriously, but isn't going to allow sin and failure to discourage them to keep moving forward in holiness, and I would not put it past a new believer to have these qualities.
So to sum that all up, does Person B, the new believer...
...looking to kill sin in his/her life?
...pursuing a daily walk with God?
...pursuing Christian community and accountability?
...confessing sin regularly and trusting in Jesus' work on the cross for his/her salvation?
Other things could be added to this list, but my main point is that spiritual health and maturity isn't necessarily so much contingent on how long the person has been a Christian as it is how great their desire is to live biblically. I could see all of these things being true of a baby Christian, maybe even moreso than the more mature believer in some respects. So as we're looking for potential lifemates, I think we should be more concerned with a person's hunger and yearning for God and for righteousness than we should be about whether or not they swear. The swearing will go away over time as they grow, but the growth can only happen if the hunger for it is there.
Side note: These should all be things we desire and encourage young believers that we know towards as we walk alongside them, and these should be things we have incorporated into our own lives as well--believing the gospel, killing and confessing sin, being in community, being accountable, studying the Bible and praying. It's easy to slack in all of these areas because the reality is that none of us will ever be a 10 on this side of heaven.