Confess

Jesus expressly told his followers that they are expected to publicly acknowledge their faith in him.  Christians who do not do so should not expect Jesus to acknowledge them.  Further, he will in turn disown people who disown Jesus.

Asking a Christian not to speak up about Jesus is asking them to be disobedient, inconsistent and hypocritical.

Luke 12: 8-9 

Jesus said, ‘I tell you, whoever publicly acknowledges me
before others, the Son of Man will also acknowledge before the angels of God.
But whoever disowns me before others will be disowned before the angels of
God.’ 

Matthew 10:32-33

So everyone who acknowledges me before men, I also will
acknowledge before my Father who is in heaven, but whoever denies me before
men, I also will deny before my Father who is in heaven.

Even in Jesus’ time people who knew him and believed in him were too fearful to acknowledge him and their faith in him. Peer group pressure, political correctness was just as strong in his time as it has been ever since.

John 12:42

Nevertheless, many even of the authorities believed in him,
but for fear of the Pharisees they did not confess it, so that they would not
be put out of the synagogue;

After his death and resurrection Jesus left his disciples with the great commission. It is still generally regarded as a commission to all Christians

Matthew 28:18-20

Then Jesus came to them and said, ‘All authority in heaven
and on earth has been given to me. Therefore go and make disciples of all
nations, baptising them in the name of the Father and of the Son and of the
Holy Spirit, and teaching them to obey everything I have commanded you. And
surely I am with you always, to the very end of the age.’

Subsequently, Jesus followers, his apostles, reinforced this teaching in the various letters to Christians.

 1 John 2:23 

No one who denies the Son has the Father. Whoever confesses the Son has the
Father also.

2 Timothy 2:12

if we endure, we will also reign with him; if we deny him,
he also will deny us;

1 John 4:2-3

By this you know the Spirit of God: every spirit that
confesses that Jesus Christ has come in the flesh is from God, and every spirit
that does not confess Jesus is not from God. This is the spirit of the
antichrist, which you heard was coming and now is in the world already.

Romans 10: 9-10

if you declare with your mouth, ‘Jesus is Lord,’ and believe
in your heart that God raised him from the dead, you will be saved. For it is
with your heart that you believe and are justified, and it is with your mouth
that you profess your faith and are saved.

The Bible leaves us with the expectation that everyone will acknowledge Jesus and worship him as God and Lord, whether they have done so in this life or not – with the indication that, at the same time, those who had not believed in him in this life will be disowned by him in the next.

Philippians 2: 9-11

Therefore God exalted him to the highest place and
gave him the name that is above every name, that at the name of Jesus every
knee should bow, in heaven and on earth and under the earth, and every tongue
acknowledge that Jesus Christ is Lord, to the glory of God the Father.

Christians are urged to avoid the failings of others and to confess Christ, witness to him, share the Gospel wholeheartedly and with confidence. They do this voluntarily, discharging the commission they have been given. Christians have nothing to boast of in their own right but can speak of God’s gift through the Lord Jesus Christ boastfully, such is their assurance that Jesus is the way, the truth and the life.

Romans 5: 9-11

Since we have now been justified by his blood, how much more
shall we be saved from God’s wrath through him! For if, while we were God’s
enemies, we were reconciled to him through the death of his Son, how much more,
having been reconciled, shall we be saved through his life! Not only is this
so, but we also boast in God through our Lord Jesus Christ, through whom we
have now received reconciliation.

1 Corinthians 9: 16-17

For when I preach the gospel, I cannot boast, since I am
compelled to preach. Woe to me if I do not preach the gospel! If I
preach voluntarily, I have a reward; if not voluntarily, I am simply
discharging the trust committed to me.

Revelation 2:4-5 

Yet I hold this against you: you have forsaken the love you
had at first. Consider how far you have fallen! Repent and do the things you
did at first. If you do not repent, I will come to you and remove your
lampstand from its place.

Revelation 3: 15-16

I know your deeds, that you are neither cold nor hot. I wish you were either
one or the other! So, because you are lukewarm – neither hot nor cold – I am
about to spit you out of my mouth.