Knowing him in 1 John 2:3-4 is NOT talking about salvation. There are a lot of backslidden and carnal Christians who do not keep God’s commandments. Knowing God is talking about being close to God in fellowship. If you are close to God as a saved person, then you are obedient to God, His inspired word and His commandments. If you are not obedient to God as a saved person, then you do not know God in a close way.
Put another way, when we got saved our POSITION in Jesus was forever settled by faith alone. But our CONDITION is conditional upon our continued obedience to God's Word. Our CONDITION changes from day to day as we change, but our POSITION is set in rock because it is grounded in God's unchanging promise of eternal life to them that believe (1st Corinthians 1:21; Titus 1:2).
If you are saved, then you are saved. Amen. But that does NOT mean that you will be obedient to him and close to him. We should be obedient to him and seek to know him and be close to him. We need his word, the King James Version Bible. God loves you and I do too. Thank you for reading my blog.