How can believers know they are born again?

In 1 John 3:14, it states that believers know they have passed from death unto life because they love the brethren. This transformation is indicative of being born again, where the believer's new nature desires worship, prayer, and fellowship with other Christians. The internal struggle between the old sinful nature and the new righteous nature is a testament to the regeneration that occurs in the new birth, leading to new affections and a holy life. Additionally, 1 John 5:18 reassures believers that those born of God do not practice sin, but instead have a new identity rooted in Christ.