At one time we too were foolish, disobedient, deceived and enslaved by all kinds of passions and pleasures. We lived in malice and envy, being hated and hating one another. But when the kindness and love of God our Savior appeared, he saved us, not because of righteous things we had done, but because of his mercy. He saved us through the washing of rebirth and renewal by the Holy Spirit, whom he poured out on us generously through Jesus Christ our Savior, so that, having been justified by his grace, we might become heirs having the hope of eternal life. This is a trustworthy saying. And I want you to stress these things, so that those who have trusted in God may be careful to devote themselves to doing what is good. These things are excellent and profitable for everyone. (Titus 3:3-8)
God saved us by his grace and mercy and we receive this gift through faith. Afterwards, we should live lives that honor and glorify our Savior and like the verse above says, we should devote ourselves to doing what is good because it is good AND beneficial to everyone, because it helps others and sets a good example for the world. But note that it nowhere says that these good works are done so that we may STAY saved. No, we are saved by grace and we are kept saved by that same grace.
Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ (Philippians 1:6)
The confession John is writing about is individual sins not a once statement of belief in Christ. He is talking to Christians in the "WE."
"IF WE( Christians) claim to be Without Sin, WE DECEIVE ourselves and the TRUTH IS NOT in US. 9 IF WE CONFESS Our SINS, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. 10 IF we claim we have not sinned, we make him out to be a liar and his word is not in us.
There are several IF s in this by John The Apostle. IF is defined as Condition, Requirement Or Stipulation in my Dictionary.
Do Not be Deceived.
May Christ Always Guide you and Bless You!