10 By the grace God has given me, I laid a foundation as a wise builder, and someone else is building on it. But each one should build with care. 11 For no one can lay any foundation other than the one already laid, which is Jesus Christ. 12 If anyone builds on this foundation using gold, silver, costly stones, wood, hay or straw, 13 their work will be shown for what it is, because the Day will bring it to light. It will be revealed with fire, and the fire will test the quality of each person’s work. 14 If what has been built survives, the builder will receive a reward. 15 If it is burned up, the builder will suffer loss but yet will be saved—even though only as one escaping through the flames.—1 Cor. 3:10-15 NIV
In our witnessing, there is only one message and that message is the foundation of Christianity. The message is this; Jesus died on the cross at Calvary to redeem us from our sinful nature. He was buried and three days later, He arose. That is the foundation upon which the church of Jesus Christ is built. We can build on that foundation by teaching others that the Bible is completely true. If we do this with understanding and wisdom from heaven, then we will be building with gold, silver and costly stones. This builder will receive his crowns and rewards in heaven. If we do it with only human understanding without the illumination of the Holy Spirit, we will be building with wood, hay or straw. This builder will narrowly make it to heaven, but suffer the loss of any rewards he thought he had earned.
22 Be merciful to those who doubt; 23 save others by snatching them from the fire; to others show mercy, mixed with fear—hating even the clothing stained by corrupted flesh–Jude 22, 23 NIV