Read 1 John 2:1-6

But those who obey God’s word truly show how completely they love him. That is how we know we are living in him. - 1 John 2:5 (NLT)

The only way to live in the truth is to come to the truth, to submit to, surrender to, open yourself up to God’s truth. Both the desire and the power to do this come from God. Then we truly live in Him.