True Christians are not "converted" they are transformed into a completely new creation opposite of what they were before and it is Christ Who does it.
Ephesians 2:10
"10 For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them."
"Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new."
No one becomes a Christian by deciding to do it. Only those who have confessed they have a sinful nature and cannot change themselves and who have trusted Christ Who paid their debt of sin for them, AND, desire to be changed by Him into a completely new person opposite of what they were before, will be saved.
Those who join Christian gatherings because it will enhance their own lives or because of pressure from family members are not born again. Motive is everything, desire to be cleansed of our sinful nature is everything.
Psalm 51:10
"Create in me a clean heart, O God, and renew a right spirit within me."
Psalm 100:3
"Know that the LORD he is God: it is he that hath made us, and not we ourselves; we are his people, and the sheep of his pasture."
If someone says they are a Christian their life should be transformed completely, if it is not, if they remain exactly as they had been before they claimed to be a Christian then they were never born again.
When Christ changes us we no longer think the same way and because we don't think the same way we act differently. We hate the sin we used to love and love the righteousness of Christ we used to despise.
Those who fight against the truth of God's Word are not born again. Those who are hostile toward and embarrassed about Christians are not born again.
John 13:35
"35 By this all people will know that you are My disciples: if you have love for one another.”
1 John 2:15-17
"15 Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him.
16 For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.
17 And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever."
1 Corinthians 2:14-15 "14 The natural man does not accept the things that come from the Spirit of God. For they are foolishness to him, and he cannot understand them, because they are spiritually discerned. 15 The spiritual man judges all things, but he himself is not subject to anyone’s judgment.…"
Another indicator that someone is saved or not is whether or not they have the fruit of the Spirit and the Love of Christ is demonstrated in their lives.
Galatians 5:22-23
"22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness, self-control; against such things there is no law."
1 Corinthians 13:4-7 "Love is patient, love is kind. It does not envy, it does not boast, it is not proud. 5 It is not rude, it is not self-seeking, it is not easily angered, it keeps no account of wrongs. 6 Love takes no pleasure in evil, but rejoices in the truth. 7 It bears all things, believes all things, hopes all things, endures all things."
The fruit of the Spirit is the qualities of Christ Who lives in the born again believer. Love is seen in the responses to people and situations as described in 1 Corinthians. Every born-again believer is the fruit of Christ.
When we encounter someone who lacks this fruit and this love then we have met someone who is a pretender, an unsaved person who has not repented and trusted in Christ.
Matthew 7:16-18 "16 You will know them by their fruits. Do men gather grapes from thornbushes or figs from thistles? 17 Even so, every good tree bears good fruit, but a bad tree bears bad fruit. 18 A good tree cannot bear bad fruit, nor can a bad tree bear good fruit."
May anyone reading this self-reflect and pray to know for sure if they have the fruit and love of Christ.