"Then shall the righteous shine forth as the sun in the kingdom of their Father. Who hath ears to hear, let him hear."
EGW directly references the concept of shining as the sun in the kingdom of their Father, which is a clear allusion to Matthew 13:43.
"Many times young men for whom heavenly intelligences have been waiting in order to number them as missionaries for God are drawn into the gatherings for amusement, and are carried away with Satan's fascinations. Instead of being afraid to continue their association with girls whose depth of mind is easily measured, whose character is of a cheap order, they become enamored of them and enter into an engagement. Satan knows that if these young men enter into an engagement with cheap-minded, pleasure-loving, worldly- minded, irreligious young women, they will bind themselves to stumbling blocks. Their usefulness will be largely crippled, if not utterly destroyed. Even if the young men themselves succeed in making an unreserved surrender to God, yet they will find that they are greatly crippled by being bound to an untrained, undisciplined, un-Christlike wife who is dead to God, dead to piety, and dead to true holiness. Their lives will prove unsatisfying and unhappy. CT 344.3"
"Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?"
The EGW passage directly applies the principle of not being unequally yoked to the context of marriage, warning against marrying someone who is not spiritually aligned. The connection is clear and meaningful.