Confess is actually a very easy word to understand.
The Greek word is homologue which literally means
“to speak alike or the same, and referred to the idea of agreement or consent (especially in law courts).”
It means to confess, profess, proclaim, acknowledge, state openly, declare with a “sense of promise,” affirmation, commitment, public intention.
Matthew 3:6 Confessing their sins, they were baptized by him in the Jordan River.
Mark 1:5 The whole Judean countryside and all the people of Jerusalem went out to him. Confessing their sins, they were baptized by him in the Jordan River.
John 1:20 He did not fail to confess, but confessed freely, “I am not the Messiah.”
Acts 19:18 Many of those who believed now came and openly confessed what they had done.
James 5:16 Therefore confess your sins to each other and pray for each other so that you may be healed. The prayer of a righteous person is powerful and effective.
1 John 1:9 If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.
The above verses apply to the Nation (and individual Jew) of Israel. The below verses apply the age of Grace.
Romans 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
2 Corinthians 9:13 Because of the service by which you have proved yourselves, others will praise God for the obedience that accompanies your confession of the gospel of Christ, and for your generosity in sharing with them and with everyone else.
1 Timothy 6:12 Fight the good fight of the faith. Take hold of the eternal life to which you were called when you made your good confession in the presence of many witnesses.
1 Timothy 6:13 In the sight of God, who gives life to everything, and of Christ Jesus, who while testifying before Pontius Pilate made the good confession, I charge you
2 Timothy 2:19 Nevertheless, God’s solid foundation stands firm, sealed with this inscription: “The Lord knows those who are his,” and, “Everyone who confesses the name of the Lord must turn away from wickedness.”