Romans 10:9-11 (Amplified Bible)

Because if you acknowledge and confess with your mouth that Jesus is Lord [recognizing His power, authority, and majesty as God], and believe in your heart that God raised Him from the dead, you will be saved. 10 For with the heart a person believes [in Christ as Savior] resulting in his justification [that is, being made righteous—being freed of the guilt of sin and made acceptable to God]; and with the mouth he acknowledges and confesses [his faith openly], resulting in and confirming [his] salvation. 11 For the Scripture says, “Whoever believes in Him [whoever adheres to, trusts in, and relies on Him] will not be disappointed [in his expectations].”

JOHN 3:16, NIV

“For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.”

This verse captures the heart of the gospel; That Jesus died for us, loves us and that eternal life is a free gift.