Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world. Titus 2:12.
Do not, because you are among unbelievers, become careless in your words, for they are taking your measure. If you sit at their table, eat temperately, and only of food that will not confuse the mind. Keep yourself from all intemperance. Be yourself an object lesson, illustrating right principles. If they offer you tea to drink, tell them in simple words [of] its injurious effect on the system. Tell them also that you do not use spirituous drinks of any kind, because you desire to keep your mind in such a condition that God can impress it with the sacred truths of His Word, and that you cannot afford to weaken any of your mental and physical powers, lest you shall be unable to discern sacred things. Thus you can sow the seeds of truth, and lead out upon the subject of keeping soul, body, and spirit in such a condition that you can understand eternal realities.
Study yourself the instruction given to Nadab and Abihu, the sons of Aaron. They “offered strange fire before the Lord, which he commanded them not.” Taking common fire, they placed it upon their censers, “and there went out fire from the Lord, and devoured them. Then Moses said unto Aaron, This is it that the Lord spake, saying, I will be sanctified in them that come nigh me, and before all the people I will be glorified” (Leviticus 10:1-3)...
The Lord desires you to be soul winners. Do not try to reveal your smartness as theologians, even of Bible truth, for by so doing you will speak to many words that will be as little understood by them as Greek... Connect yourself firmly with Christ, and present the truth as it is in Him. Work as Paul worked. Wherever he was, whether before scowling Pharisees or Roman authorities, rich or poor, learned or ignorant, the cripple at Lystra or the convicted sinners in a Macedonian dungeon, he lifted up Christ as One who hates sin and loves the sinner, the One who bore our sins that He might have full power and authority to impart to us His righteousness.
Hearts cannot fail to be touched by the story of the atonement. Those who realize the necessity of keeping the heart under the control of the Holy Spirit will be enabled to sow seed that will spring up unto eternal life.—Manuscript 23, November 24, 1890, “Diary.”
Reference: E.G. White, "The Upward Look," p. 342.