True to Jesus’ promise, the Spirit gives the apostles “all truth” by inspiring their speech and their writings (1 Corinthians 2:13; 14:37; Ephesians 3:1-5; 1 John 4:6; Revelation 1:1-3 cf. 2 Peter 1:3; Jude 1:3). We have their writings in the New Testament. Together with the Old Testament, we now have “all Scripture” that fully equips us for our mission.
Do your best to present yourself to God as one approved, a worker who has no need to be ashamed, rightly handling the word of truth (2 Timothy 2:15).
All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work (2 Timothy 3:16-17).
Effective evangelism requires the hard work of learning and correctly using “the word of truth.” The less people hear our human ideas, and the more they hear from the Spirit, the more they will be convinced and convicted. In a sense, we get out of the way. We let the Bible speak. When questions arise, seek the answers from Scripture. That way, the main relationship is between the person and God, not merely between two humans. What people feel about us is far less consequential. The person who rejects the word rejects its Author and will be held accountable.
The one who rejects Me [Jesus] and does not receive My words has a judge; the word that I have spoken will judge him on the last day (John 12:48).
On the other hand, the learner who accepts the word responds to its Author and will be saved.
When you received the word of God, which you heard from us, you accepted it not as the word of men but as what it really is, the word of God, which is at work in you believers (1 Thessalonians 2:13).
Receive with meekness the implanted word, which is able to save your souls (James 1:21).
You have been born again, not of perishable seed but of imperishable, through the living and abiding word of God (1 Peter 1:23)