1 Samuel 18:1 (ESV): As soon as he had finished speaking to Saul, the soul of Jonathan was knit to the soul of David, and Jonathan loved him as his own soul.
Of course, the word "knit" means to be united or to be tied. Other scriptures referencing soul ties include Genesis 2:24, Mark 10:7-9, 1 Corinthians 6:16, Genesis 34:1-3, 2 Corinthians 6:14, and Acts 4:32. The second book of Corinthians gives an interesting take on soul ties.
2 Corinthians 6:14 (ESV): Do not be unequally yoked with unbelievers. For what partnership has righteousness with lawlessness? Or what fellowship has light with darkness?
Merriam-Webster Dictionary defines the word "yoke" this way: a wooden bar or frame by which two draft animals (such as oxen) are joined at the heads or necks for working together. A draft animal is an animal used for carrying heavy loads. So, when God tells us to not be unequally yoked with unbelievers, He is telling us:
- Do not be in agreement with unbelievers (see 1 Corinthians 15:33).
- Do not walk with the lost (Proverbs 13:20).
- Cut away from you anyone who causes you to sin (Matthew 5:30).
- If you yoke yourself with an unbeliever, you (the believer) will carry the burden of the relationship.