It makes a big difference who we believe God is.
And how we approach Him.
This should go without saying; especially when speaking with Christians. Because those who know the Lord Jesus Christ as their Savior possess clear instructions on who He is and how they must come to Him.
The Christian understands that the Bible is the instruction guide for both those questions. 66 books from Genesis to Revelation. No more; no less.
Veer away from that written collection and you introduce problems. Grave problems.
Establishing the certainty of truth and authority is answered simply. Truth is known by those who find it.
“Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed; And ye shall know the truth, and the truth will make you free.” (John 8:31,32)
God promises to manifest Himself to those who believe His words. As the sheep know the shepherd’s voice, those in whom the Spirit dwells, know His voice from all others.
“My sheep hear my voice, and I know them, and they follow me.” (John 10:27)