John 14:24 "He who does not love Me does not keep My words; and the word which you hear is not Mine but the Father's who sent Me."
The words spoken by our Lord Jesus were the very words of the Farther Himself. So God cannot contradict His own words. God is fair to everyone by teaching us how to judge ourselves whether we love Him or not. If we keep His words, we love Him, but if we do not keep His words then we do not love Him.
1 John 2:5-6 But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him. He who says he abides in Him ought himself also to walk just as He walked.
This is another test. Whosoever loves Jesus will be like Him - washes the feet of his servants or staff (disciples); full of humility, mercy, love, goodness and compassion; rejoices in giving, helping, charities, sacrifices, persecutions and sufferings; prays, forgives and blesses enemies; etc.
1 Peter 3:8-10 Finally, all of you be of one mind, having compassion for one another; love as brothers, be tenderhearted, be courteous; not returning evil for evil or reviling for reviling, but on the contrary blessing, knowing that you were called to this, that you may inherit a blessing.
Deut 28:45-47 "Moreover all these curses shall come upon you and pursue and overtake you, until you are destroyed, because you did not obey the voice of the Lord your God, to keep His commandments and His statutes which He commanded you. And they shall be upon you for a sign and a wonder, and on your descendants forever. Because you did not serve the Lord your God with joy and gladness of heart, for the abundance of everything,"
For all those who did not keep His words were cursed in the OT. Jews were the people of God, and today Christians are the people of God. Since God does not change and is just, He will also chastise all those who refuse to keep His words with pains, worries, sorrows, sufferings, losses, problems, defeats, sicknesses, etc. just like in the OT.
We thank God that in Christ Jesus, all our sins are forgiven once we repent of them, thus freeing us from His chastisements.
1 Tim 6:3-5 If anyone teaches otherwise and does not consent to wholesome words, even the words of our Lord Jesus Christ, and to the doctrine which accords with godliness, he is proud, knowing nothing, but is obsessed with disputes and arguments over words, from which come envy, strife, reviling, evil suspicions, useless wranglings of men of corrupt minds and destitute of the truth, who suppose that godliness is a means of gain. From such withdraw yourself.
Doctrines of God always lead us to godliness and holiness, so that we can conform to His image. But false doctrines and distorted truth will always lead to divisions and destruction (usually pleasing and satisfying the flesh or carnal man).
Brethren, since God wants us to decide our own destinations, let us ensure that He has full authority over us and is in complete control of our lives. Thus, when we keep His word, in this world we will inherit an abundant life led by the Spirit, and after that inherit the kingdom of God by His good works in us.