I agree with Jason above. I also want to add the understanding that unequally yoked means to be placed in a position where you are not productive or being utilized properly for the purpose you were created, either as one who prepares and plants the seed, or one who harvests and meant to eat the seed.
When Paul made the allusion to not be unequally yoked, it refers to being attached to a ploughing tool. Remember Paul speaks heavily on the purpose of God’s workers in 1 Corinthians and we cannot take a verse out of the context it was written but read both letters in whole, as the first relates to the second and the second to the first.
Paul starts 2 Corinthians 6 in verse 1, " As God’s co-workers we urge you not to receive God’s grace in vain."
To understand this allusion of yoked, a team of eight oxen were attached to the tool, yoked four abreast. If the soil was light, four Oxen were attached to the tool, yoked two abreast (half plough); if the soil was very heavy, ten to twelve oxen were attached five or six abreast.
The purpose of ploughing the soil was to get it prepared for the seed which was to be planted. To be unequally yoked means for light soil having a team of twelve, and for heavy soil a team of two. They are ineffective and unproductive, unequally yoked for the purpose in which they were created. If the land is over-ploughed or under-ploughed the seed is planted in vain, since it will not grow, or get choked up and die.
The oxen, are the co-workers of God; the seed is the Gospel, God’s grace; the land is the world of which the Gospel is sent to feed and give life.
Now, we move on to 2 Corinthians 6 verse 14 “Do not be yoked together with unbelievers.”
If the oxen are paired up with goats, sheep or dogs, the oxen become unproductive and pull the weight of the ploughing disproportionally because goats, sheep and dogs were never meant to plough the land. The oxen get burnt out, and the land once again will not allow the seed to grow, or it will get choked up and die. That very seed was meant to feed the goats, sheep and the dogs and they will go hungry and die.
The oxen, are the co-workers of God; the seed is the Gospel, God’s grace; the land is the world of which the Gospel is sent to feed and give life; and that which is not oxen, the unbeliever, was never meant to be part of that work.
This is not talking about marriage, culture, etc. This is talking about encouraging one another and honour those who have been sent out ahead to plough the ground and not hindering them by adding or subtracting to the Gospel entrusted to them, and secondly not putting a yoke on those who were meant to be fed by the Grace of God and were never meant to be yoked with God’s co-workers in the first place but when the harvest is ready, are to be fed by it.
I hope this helps.