The same Jesus who's blood cleanses us form "all sin" knows our future sins just as much as our past sins.
1 John 3 (LEB) 3 See what sort of love the Father has given to us: that we should be called children of God, and we are! Because of this the world does not know us: because it did not know him. 2 Dear friends, now we are children of God, and what we will be has not yet been revealed. We know that whenever he is revealed we will be like him, because we will see him just as he is. 3 And everyone who has this hope in him purifies himself, just as that one is pure.
Maybe to you. To me, "all sin" indicates "all sin".
Isaiah 46:3-4 (LEB)
3 “Listen to me, house of Jacob,
and all the remnant of the house of Israel
who have been carried from the belly,
who have been carried from the womb:
4 Even to your old age I am he;
even to your advanced age I myself will support you.
I myself have made you,
and I myself will carry you,
and I myself will support you,
and I will save you.
Umm, there is no mention of past sins either. What's mentioned is cleansing of "all sin".
God knows your wanderings in all your past, present and future days:
Psalm 139:3 (LEB) You search out my wandering and my lying down,
and are acquainted with all my ways.
Psalm 139:16 (NASB)
Your eyes have seen my unformed substance;
And in Your book were all written
The days that were ordained for me,
When as yet there was not one of them.
Okay. But the verse talks about actual cleansing of sin, not actual cleansing of 'not sin'. Oh, and "all sin"!
To "know Him" is to; "
know that whenever he is revealed we will be like him."
When you/I confess sins "to one another", they do not catch the Lord Jesus Christ by surprise. He already knew them, way before confessing them to another man.
Jesus knows your past present and future (including your sins). At least my Jesus does.
John 4:10 (LEB) 10 Jesus answered and said to her, “If you had known the gift of God and who it is who says to you, ‘Give me water to drink,’ you would have asked him, and he would have given you living water.”
John 4:17-18 (LEB) 17 The woman answered and said to him, “I do not have a husband.” Jesus said to her, “You have said rightly, ‘I do not have a husband,’ 18 for you have had five husbands, and the one whom you have now is not your husband; this you have said truthfully!”