"The religion of Jesus softens whatever is hard and rough in the temper, and smooths whatever is rugged and sharp in the manners. It makes the words gentle and the demeanor winning. Let us learn from Christ how to combine a high sense of purity and integrity with sunniness of disposition. A kind, courteous Christian is the most powerful argument that can be produced in favor of Christianity. GW 122.1"
"Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven."
Both passages connect good works and a positive demeanor with reflecting God's character and drawing others to Him.
"Kind words are as dew and gentle showers to the soul. The Scripture says of Christ, that grace was poured into His lips, that He might “know how to speak a word in season to him that is weary.” [ Isaiah 50:4 .] And the Lord bids us, “Let your speech be alway with grace” “that it may minister grace unto the hearers.” [ Colossians 4:6 ; Ephesians 4:29 .] GW 122.2"
"The Lord God hath given me the tongue of the learned, that I should know how to speak a word in season to him that is weary: he wakeneth morning by morning, he wakeneth mine ear to hear as the learned."
Ellen White directly references Isaiah 50:4 in this passage.
"Let your speech be alway with grace, seasoned with salt, that ye may know how ye ought to answer every man."
Ellen White directly references Colossians 4:6 in this passage.
"Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers."
Ellen White directly references Ephesians 4:29 in this passage.
"Some with whom you are brought in contact may be rough and uncourteous, but do not, because of this, be less courteous yourself. He who wishes to preserve his own self-respect must be careful not to wound needlessly the self-respect of others. This rule should be sacredly observed toward the dullest, the most blundering. What God intends to do with these apparently unpromising ones, you do not know. He has in the past accepted persons no more promising or attractive to do a great work for Him. His Spirit, moving upon the heart, has roused every faculty to vigorous action. The Lord saw in these rough, unhewn stones precious material, which would stand the test of storm and heat and pressure. God does not see as man sees. He does not judge from appearances, but searches the heart and judges righteously. GW 122.3"
"Be kindly affectioned one to another with brotherly love; in honour preferring one another;"
The EGW passage echoes the sentiment of Romans 12:10, emphasizing kindness, respect, and preferring others. While not a direct quote, the principle of valuing others and showing them honor is clearly present in both texts.