You’ll know you are saved because the Holy Spirit will bear witness (confirm/establish) with your spirit (innermost being, NOT human reasoning or logic) that you are saved. It’s not a logical dialogue, it’s a spiritual understanding and knowing… the Holy Spirit speaks directly to your spirit and you know it is True, you are saved.
For you did not receive the spirit of bondage again to fear, but you received the Spirit of adoption by whom we cry out, “Abba, Father.” The Spirit Himself bears witness with our spirit that we are children of God,
https://www.biblegateway.com/passage/?search=Rom.8.15,Rom.8.16&version=NKJV
If you are not sure if you are saved, simply talk to God… repent of all your sins, receive the Blood and Body of Jesus Christ. His Blood removes your sins and His Body gives you the Righteousness of God. All your fear, guilt and shame is gone.
You are sealed with God’s Holy Spirit, get water baptized as an outward public confession of your faith in Jesus Christ and evidence you are in blood covenant with Him.
Ask the Father, in the Name of Jesus Christ for the Gift of the Holy Spirit to be released inside of you and be filled with the Holy Spirit - the power of God to witness of Jesus Christ in the Earth.
Study God’s Word with the Holy Spirit… He will teach you.
The HS bears witness that we walk by faith, not by sight, and by hope, not by having. The HS who inspired 1John 2:9 also inspired Hebrews 6:4-6, 10:35-39, Rom. 11:22, 1Cor. 15:2, Col. 1:22-23, 2Thes. 1:4-5, 2Tim. 2:12, Heb. 3:6&14, 10:35-36, Jam. 1:12, 2Pet. 1:10-11, 2:20, 1John 2:24-25 and Rev. 2:10.
The issue is not believing you ARE saved, but rather knowing you WILL not leave. IOW, in order to have the correct understanding, it is necessary to harmonize ALL of GW regarding it, and GW/the HS taught me the categories listed in post #5. You will note that 1John 2:19 refers to category "d", whereas the 16 Scriptures I just cited refer to category "e".