By this we can be sure that we have come to know Him: if we keep His commandments. 1 John 2:3

“If anyone keeps His word, the love of God has been truly perfected in him. By this we know that we are in Him. But the one who says, ‘I have come to know Him,’ and does not keep His commandments, is a liar, and the truth is not in him; for  Jesus said, If you love Me, you will keep My commandments.”