Acts 16:31 says "They answered: Believe in the Lord Jesus, and you will be saved, you and all your household." God knows the deepest part of our heart and knows if we have faith, through it we are saved, Romans 10: 09-13 says that if we confess with our mouths that Jesus is the Lord and believe in our heart that God raised him from the dead will be saved, because with the heart one believes for justice but with the mouth one confesses for salvation.