'Believe' in the Bible

This is His commandment, that we believe [with personal faith and confident trust] in the name of His Son Jesus Christ, and [that we unselfishly] love and seek the best for one another, just as He commanded us.

We have come to know [by personal observation and experience], and have believed [with deep, consistent faith] the love which God has for us. God is love, and the one who abides in love abides in God, and God abides continually in him.

The one who believes in the Son of God [who adheres to, trusts in, and relies confidently on Him as Savior] has the testimony within himself [because he can speak authoritatively about Christ from his own personal experience]. The one who does not believe God [in this way] has made Him [out to be] a liar, because he has not believed in the evidence that God has given regarding His Son.

These things I have written to you who believe in the name of the Son of God [which represents all that Jesus Christ is and does], so that you will know [with settled and absolute knowledge] that you [already] have eternal life.