1 John 2:5

But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him.

If anyone obeys His word, love for God is truly made complete in them.

Whoever habitually keeps His word and obeys His precepts and treasures His message in its entirety, in him the love of God has truly been perfected, it is completed and has reached maturity.

Romans 10:16-17

16 But they have not all obeyed the gospel. For Isaiah says, “Lord, who has believed our report?” 17 So then faith comes by hearing, and hearing by the word of God.

Faith comes from hearing the message, and the message is heard through the word about Christ.
Faith comes from hearing what is told, and what is heard comes by the preaching of the message concerning Christ.

1 Corinthians 16:22

If anyone does not love the Lord Jesus Christ, let him be accursed. O Lord, come!

If anyone does not love the Lord, let that person be cursed!
If anyone does not love the Lord, does not obey and respect and believe in Jesus Christ and His message, he is to be accursed.

Come, Lord!
Maranatha, O our Lord, come!