By this we know [and have come to understand the depth and essence of His precious] love: that He [willingly] laid down His life for us [because He loved us]. And we ought to lay down our lives for the believers.
It was because of love that Jesus was willing to lay down His life for us. It was not done out of obligation or because of something He was forced to do. Jesus came to this earth simply because He loved us and the offer of salvation is open to any who would accept it.
To follow Jesus Christ simply requires faith. It requires us to believe that Jesus is in deed the Son of God, that He died on a cross, that He rose again, and to put our full trust in Him. As we simply place our faith in Jesus Christ we supernaturally become God’s sons and daughters. We are adopted into God’s family and we are able to approach God the Father with confidence because we have been declared righteous because of who Jesus is.