For the love of God is this, that we obey his commandments. And his commandments are not burdensome.
The first thing to note is that John intimately connects love for God with obedience to his commandments. In this manner, he is merely echoing what he heard Jesus say on the night in which he was betrayed, during the upper room discourse: You are my friends if you do what I command you (John 15:14). It seems to me that John is far from any notion that our continued fellowship and friendship with God is unaffected or indifferent to our behavior. On the contrary, the greatest commandment is that we love God with everything that we have, and if we do this, certainly we will obey the other commandments he gives us as well.
Our sin -- its frequency, its mode, our contrition or lack thereof over it -- reveals to us a bit about ourselves. Specifically, it teaches us whether or not we really love God, as we might say that we do, or whether our love prefers something else. Thomas Aquinas wrote: The very fact that anyone chooses something that is contrary to divine charity, proves that he prefers it to the love of God, and consequently, that he loves it more than he loves God (ST Ia-IIae, 88, 2). So we have to ask ourselves tough questions and come to terms with our actual state. If we prefer something else to God, we ought to ask why, and how we have been caught in the trap of idolatry.
What is especially fascinating is that John says that God's commandments are not burdensome. To the average person, this would seem very much contrary to experience! How can John say that it isn't burdensome constantly to have to say 'no' to the various impulses which arise within you -- whether they be to sexual immorality or anger or mistreatment of others or cheating or whatever?
It seems to me that the burdensomeness of the commandments arises not from themselves but from us. In other words, the commandment is not burdensome in itself because it is supposed to express that life which is natural and authentic for human beings, created ad imaginem Dei. To love your neighbor ought to be natural and normal and fulfilling for the human person, because that is what it means to be like God, and the human creature was intended to be like God. Rather, the commandment can seem burdensome only because we are disordered, because we are so far from exemplifying that which God intends for us. And more than anything, it is out of a love for God that the commandments seem burdensome, because we do not yet love God enough to do what he wants.
Thomas Aquinas comments thus in his commentary on the Gospel according to Matthew:
Likewise, in regard to circumstances there are many adversities; hence "All who desire to lead a godly life in Christ Jesus will suffer persecution" (2 Tim 3:12). But they are not burdensome, because they are seasoned with the condiment of love; for when a person loves someone, it is not a burden to suffer anything for him. Hence love makes easy all difficult and impossible things. Therefore, if one loves Christ properly, nothing is difficult for him; consequently, the New Law does not impose a burden (Super Evangelium S. Matthaei, caput 11, lectio 3, §30).The love of God is what makes his commandments to be light rather than burdensome. Just as a man might tell a woman whom he loves that he would do anything for her, or a mother might do anything for the children that she loves, so also a person who loves God is willing to undergo anything for his sake. Thus, this beautiful line from Mechthild of Magdeburg:
Three things make the soul worthy of this way so that it recognizes it and walks in it. Firstly, that it wills to come to God, renouncing all self-will, joyfully welcoming God's grace and willingly accepting all its demands against human desires. The second thing which keeps the soul in the way is that all things are welcome to it save sin alone. The third thing makes the creature perfect in the way, namely, that it does all things to the glory of God, so that even its smallest desire will be as highly prized by God as if it were in the highest state of contemplation possible to humanity (The Flowing Light of the Godhead, 27).But how can we love God? Can we just produce it within us?
The obvious answer is no. We do not love God by making ourselves do it, any more than we make ourselves love other people. But God makes us to love him by revealing to us who he is and how much he loves us: through the self-offering of Christ, and through the Holy Spirit which testifies within us that God loves us and has chosen us for salvation. This is what I have been saying over the course of my last few posts on 1 John: the Holy Trinity brings us to itself, the Holy Spirit helping us to believe that Christ is the Son of God, given for the sins of the whole world, the demonstration of the love of the Father for all.
So when we find the commandments of God burdensome, we ought to look deep within ourselves and try to find the voice of the Holy Spirit, prompting us towards something better. But if we hear no such voice, if we feel no such desire, at the very least we see that something is wrong -- which is itself a sign of the presence and work of the Holy Spirit! So we ought to ask of God, who gladly will give the Holy Spirit to all who ask of him (Luke 11:13).