Let me start answering your good question by looking at a couple of verses that are appropriate for your question.  1 John 1:9 tells us, “If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.”  For the believer, the continual confessing of our sins is essential to a healthy and godly life.  I think we can all agree that, even though we are saved, we still sin.  Quite honestly, we all probably sin on a daily basis.  In fact, the previous verse, 1 John 1:8 says, “If we say that we have no sin, we deceive ourselves, and the truth is not in us.”  Yes, even saved people sin, but the Lord wants us to confess those sins to Him, so that He might, in a practical sense, forgive those sins and cleanse us from all unrighteousness. 

Notice that this forgiveness is not based on the Lord’s mercy and grace, but on His faithfulness and righteousness (justice).  It was by the Lord’s mercy and grace that He saved us when we put our faith in the Lord Jesus as our savior.  Now that we belong to Him, His practical forgiveness is based on the truth that God is faithful to what He has promised and is righteous in forgiving us.  Indeed, God’s promises of mercy, to which He is faithful, are in accordance with His justice.  I trust that with these thoughts, all can clearly see that the Lord wants all His children to be aware and contrite when we sin and confess those sins to Him.  He will always forgive and cleanse us when we do that.

Let’s back up one more verse in 1John and consider verse 7, which says, “But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.”  ALL SIN!  In John 13:10, the Lord declares that the believer is “completely clean.” (NKJV).  It is on the basis of the shed blood of the Lord Jesus that all believers are cleansed by erasing the stain of sin, keeping us cleansed from sin in all its forms and manifestations. How powerful and thorough is the work of the Lord on the cross when He redeemed us with His own precious blood. (1 Peter 1:18-19).

Some fear that they may put their trust in the Lord Jesus, follow Him faithfully all their lives, then lose their salvation by forgetting to confess some sin or sins.  This is simply contrary to the truth of God’s Word when the Lord pronounces, “And I give unto them eternal life; and they shall NEVER PERISH, neither shall any man pluck them out of my hand.” (John 10:28).  We are assured in Colossians 2:13-14, “And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, HAVING FORGIVEN YOU ALL TRESPASSES; Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross.” 

The strength of our salvation is found in the finished work of the Lord Jesus Christ on the cross where He died for our salvation.  The strength for our daily walk is found in confessing our daily sins on a daily basis.  When we continue in God’s Word daily, He gives us strength to resist sin and live according to His Holy Word and will.  Additionally, we are assured by the Lord, “I will never leave thee, nor forsake thee.” (Hebrews 13:5).  (CC)  (687.2)