When you believe in Jesus as the Son of God who loves you, you can never be the same person again.
Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new. 2 Corinthians 5:17
He has delivered us from the power of darkness and conveyed us into the kingdom of the Son of His love...Colossians 1:13
When you believe in Jesus and trust him to direct and transform your life, he makes you a son or daughter of the eternal God.
See what kind of love the Father has given to us, that we should be called children of God; and so we are... Beloved, we are God’s children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is. 1 John 3:1-2 (ESV)
When you decide to believe in Jesus, God changes your whole nature, and begins to transform you into the wonderful person He designed you to be, full of love and goodness like Jesus himself.