Because if you confess the Lord Jesus with your mouth, and believe in your heart that God raised Him from the dead, you will be saved.
(Rom 10:9)
But as many as received him, to them gave He power to become the sons of God, even to them that believe on his name:
John 1:12
He that believes on the Son hath everlasting life: and he that believes not the Son shall not see life; but the wrath of God abides on him.
John 3:36
Jesus answered and said unto them, This is the work of God, that you believe on him whom he hath sent.
John 6:29
Jesus saith unto her, Said I not unto thee, that, if you wouldst believe, you should see the glory of God?
John 11:40
Let not your heart be troubled: you believe in God, believe also in me.
John 14:1
But these are written, that you might believe that Jesus is the Christ, the Son of God; and that believing you might have life through his name.
John 20:31
And Philip said, If you believe from all the heart, it is lawful. And answering he said, I believe Jesus Christ to be the Son of God. And he commanded the chariot to stand still. And both went down into the water, both Philip and the eunuch; and he baptized him. But when they came up out of the water, the Spirit of the Lord caught away Philip. And the eunuch did not see him any more; for he went his way rejoicing.
Act 8:37-39
And they said, believe on the Lord Jesus Christ, and you will be saved, you and your household.
Act 16:31
…even the righteousness of God through faith of Jesus Christ toward all and upon all those believing; for there is no difference,
Romans 3:22
But the scripture has concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
Galatians 3:22
But wihtout faith it is impossible to please him: for he that comes to God must believe that he is, and that he is a rewarder of them that diligently seek him.
Hebrews 11:6
And this is His commandment, that we should believe the name of His Son, Jesus Christ, and love one another, even as He gave command to us.
1 John 3:23
I wrote these things to you, the ones believing in the name of the Son of God, that you may know that you have everlasting life, and that you may believe in the name of the Son of God.
1 John 5:13