As it is used in Scripture, especially in the gospel of John, it connotes the concept of accepting the facts of the gospel, but included in that is the concept of trust. To believe in Christ for salvation means one believes in what the Bible says about Jesus Christ—He is God’s Son, the God-man Savior, that He personally died for our sin, was raised from the dead, and that one turns from self-trust or indifference and trusts in Christ alone for their salvation. Belief in the facts about Christ as stated in the Bible and trust in them (the facts about Christ) is the only sufficient means of salvation.
This is supported by the fact that in the gospel of John, which uses the term believe some 95 times, it usually includes a preposition like “in, into, upon.” This means that salvation is a gift, not a work of righteousness. The only thing we can do is believe or trust in the person of Christ according to the message of the Bible.
Please note: ‘faith’ or ‘believe’ in themselves are absolutely worthless. Faith can only lead to salvation when one’s faith is in the right object. Faith in faith will always leave a person lost, without God, and in his sins.
Another term that may help here is the term repentance when used in connection with salvation. Repentance basically means to change one’s mind about something. We cannot save ourselves by our works or religious good deeds. We all fall short of God’s holiness. But as the expression of His love, God sent His Son to die for our sin. This means a person must change his mind about his ability to save himself or quit being indifferent and turn to Christ, trusting in His death for their sin.
The gospel is the Bible’s good news message about Christ and this gospel is the power of God unto salvation to everyone who believes (Rom. 1:16). Thus, if one has never trusted in Christ, the first step toward finding and knowing God is to believe the facts about Jesus Christ and trust in Him as one’s personal Savior.