Matthew 10:32,33
32"Whoever acknowledges me before men, I will also acknowledge him before my Father in heaven. 33But whoever disowns me before men, I will disown him before my Father in heaven."
Romans 10:8-10
8But what does it say? "The word is near you; it is in your mouth and in your heart," that is, the word of faith we are proclaiming: 9That if you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised him from the dead, you will be saved. 10For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved.
Acts 1:8
8But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth."
1 Peter 3:15
15But in your hearts set apart Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect.