There are different ways of sharing the Gospel and different experiences people have when they become Christians. However, the core truths of the Gospel must be present along with Jesus’ call to “repent and believe,” which involves being born again of God’s Spirit (Mark 1:15; John 3:3.
Some say that in order to receive this transforming gift of salvation all one needs to do is believe, which is true. But when they use the word believe, they take it out of the biblical context, which always infers a change of heart and direction or rather the ingredients of knowledge, assent and trust. Because of this, true belief always includes repentance -- turning from trusting in ourselves to trusting in Christ alone to save us. Isaiah 30:15 emphasizes this as a basic, biblical principle. “In repentance and rest is your salvation. In quietness and trust is your strength.”
Proponents of easy believism often refer to the act of making a decision to follow Christ as if they are talking about merely believing something exists and that it's good. But Scripture never talks about salvation through this lens except in a negative way. James writes, “You believe that there is one God. Good! Even the demons believe that — and shutter” (James 2:19). Instead, Jesus began his earthy ministry with the call to repentant faith when he said, "Repent and believe" (Mark 1:15). He is repeatedly referred to as Lord in the Gospels and calls for his disciples and us to "Take up your cross and follow me" (Matthew 16:24). He says that we need to carefully count the cost before putting our trust in him -- loving him so much that we are willing to forsake all to be his disciples (Luke 14:33).
Jesus' instruction to Nicodemus are his very words to us -- we must be born again of the Spirit. While many come to faith in Christ as children and cannot remember turning from a dark lifestyle of rebellion, it's important that we all know that we have been born again. This radical regeneration is not a moving around of furniture as one pastor is known to say, but is a dying to sin and the flesh and being made new in the likeness of Christ through the indwelling Holy Spirit (1 Corinthians 15:20). This transfer from the kingdom of darkness to the kingdom of light cannot be missed just as one could not miss it if they were brought up from the dead and given new life in their lungs (Colossians 1:13).
The charge from the apostle Paul for all is to "examine yourself to be sure you're in the faith" (2 Corinthians 13:5). I've included a link below to a Desiring God article that provides clear evidences that a person has experienced regeneration. In reading the article I hope you will know with certainty that you have been born again. And if you realize that you are not, you will get on your knees today, repent of your sins and surrender your heart and life to Christ — declaring him to be your Lord and Savior.
https://www.desiringgod.org/articles/am-i-truly-born-again