Matthew 22:37
And He answered him, "'You must love the Lord your God with your whole heart, your whole soul, and your whole mind.'
Acts 11:23
When he reached there and saw the spiritual blessing God had given them, he was delighted, and continuously encouraged them all with hearty purpose to continue to be devoted to the Lord;
2 Corinthians 11:2-3
For I feel a divine jealousy for you, as I betrothed you to Christ, to present you as a pure bride to her one husband.
2 Timothy 4:8
Now the crown for doing right awaits me, which the Lord, the righteous Judge, will award me on that day, and not only me but also all who have loved His appearing.
1 John 5:2-3
This is how we can be sure that we love the children of God, by continuing to love God and to obey His commands.