Are you reading through all of what I put?
I did a small edit to show exactly what confessing Christ means because a lot of people think they are Christians simply because they believe in God or because their family is X denomination, but that is as far as the thought goes. 'Cultural Christianity' is not confessing Christ.
If they confess Christ they have the Holy Spirit.
They know because God's word says so.
Ephesians 1:13-14
13 And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit
We have the spirit because the Word tells us that we do. So it comes back to faith.
Which then goes back to understanding what the full meaning of confessing Christ means. If this person does not have the Holy Spirit then they are not confessing Christ.
Copy paste from my other post.
“Whoever acknowledges me before men, I will also acknowledge him before my Father in heaven.” Matthew 10:32 (NIV)
The word ‘acknowledge’ (or confess) in the Greek is homo = ‘one’ plus logeo = ‘word.’ It literally means “to be of one word.” To confess Jesus is to be of one word with Him, to say what He says.
Jesus says, “I am the way and the truth and the life” (John 14:6). To be of one word with Him is to say, “For me, Jesus is my way and my truth and my life.” You believe it. You own it. You do not say, “This is what Jesus says, but I have a different view.” Or “I am not so sure about that.” You say, “I will follow Him as my Lord. I will listen to Him as my Teacher. I will trust in Him as my Savior.”
Jesus is the Word. If we read his words and say we have a different view from what is written, then we are not confessing Christ.
Yes to all of those.
Then I am not understanding your original inquiry as I felt I covered all of it. If a Christian knows and follows and treasures God's word he or she won't be steered wrong by false teachers because they will know by the scriptures and by the Holy Spirit.
I am simply talking about the quiet leading and discernment that the Holy Spirit gives. Even a new Christian should feel in their spirit if something is not of God, even if they don't yet understand why. They should take that as a hint to go look up the scriptures about it and ask a Christian mentor.
Jesus said
John 5:46
If you believed Moses, you would believe me, for he wrote about me.
Jesus says we need to belive Mosses, so if we are confessing Christ we will. That means believing in both the Old and New Testament.
A false teacher will say
"what their itching ears want to hear." It will be agreeable to the people who are deceived by it. They either won't check scripture or will disagree with it and so be easily led by something persuasive. It will appeal to their emotions, greed, or knowledge.
When we trust the Word we believe it even when we don't like the message, even when it would be easier to go along with the mainstream. The Word becomes the ultimate source of truth.
Yes very possible- if people do not have their eyes on God if they have backslid and let life 'choke the word out".
Mark 4:19
but the worries of this life, the deceitfulness of wealth and the desires for other things come in and choke the word, making it unfruitful.Matthew 24:24
For false messiahs and false prophets will appear and perform great signs and wonders to deceive, if possible, even the elect.
Just because someone gets deceived once does not mean they always will. Peter was a disciple and still he sank beneath the water when he tried to walk on water to Jesus. In that moment it was the 'worries of life' that made him sink. No one is perfect, we are all a work in progress.