“For this is the love of God, that we keep his commandments: and his commandments are not grievous.”  1 John 5:3

He leaves with no doubts:
“And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment.”  1 John 3:23
It’s not a suggestion that you believe in the name of his son Jesus Christ, it’s a commandment- God expects all men to obey the faith: Romans 1:5
Jesus said:
“Jesus saith unto him, I am the way… no man cometh unto the Father, but by me.”  John 14:6
This is compulsory, there are no other options, routes or paths- Jesus is THE way, and God validated him and his gospel by raising him up from the dead and causing his message to prolong through us. We are now ambassadors of Christ. Now that you have believed in Jesus, live in his name:
“And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him.”  Colossians 3:17
To do that he emphasizes:
“These things have I written unto you that believe on the name of the Son of God… that ye may believe on the name of the Son of God.”  1 John 5:13
Get this- it is possible to believe in Jesus and live your life unconscious of the efficacy and power of that name- God commands that you don’t! Believe; use the name, Jesus wants you to:
“Hitherto have ye asked nothing in my name: ask, and ye shall receive, that your joy may be full.”  John 16:24