"Salt must be mingled with the substance to which it is added; it must penetrate and infuse in order to preserve. So it is through personal contact and association that men are reached by the saving power of the gospel. They are not saved in masses, but as individuals. Personal influence is a power. We must come close to those whom we desire to benefit. MB 36.1"
"Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men."
The EGW passage directly uses the metaphor of salt mingling with substance to illustrate the need for personal contact in spreading the gospel, which is a clear allusion to Matthew 5:13 where believers are called the 'salt of the earth.'
"And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God."
The EGW passage uses the word 'transforming' which is a clear allusion to Romans 12:2, which speaks of being transformed by the renewing of your mind.
"As they listened to the words of Christ, the people could see the white salt glistening in the pathways where it had been cast out because it had lost its savor and was therefore useless. It well represented the condition of the Pharisees and the effect of their religion upon society. It represents the life of every soul from whom the power of the grace of God has departed and who has become cold and Christless. Whatever may be his profession, such a one is looked upon by men and angels as insipid and disagreeable. It is to such that Christ says: “I would thou wert cold or hot. So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of My mouth.” Revelation 3:15, 16 . MB 36.4"
"Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men."
The EGW passage directly references the salt losing its savor and being cast out, which is a clear and explicit allusion to Matthew 5:13. The passage also connects this to the lukewarmness described in Revelation, further solidifying the connection.