This is my commandment, that you love one another, as I have loved you. Greater love than this no man has, that a man lay down his life for his friends. You are my friends, if you do the things that I command you. I will not now call you servants: for the servant knows not what his lord does. But I have called you friends because all things, whatsoever I have heard of my Father, I have made known to you. You have not chosen me: but I have chosen you; and have appointed you, that you should go and should bring forth fruit; and your fruit should remain: that whatsoever you shall ask of the Father in my name, he may give it you. These things I command you, that you love one another. [John 15:12-17]
The Lord Jesus says that we are his friends if we do what he commands. If that is true, then is it in any way credible to suppose that what we do is irrelevant to our standing as Christians before God? Of course not. Is it reasonable to suppose that what we do as Christians does not matter? Of course not. Why would Christ give us commands if our obedience doesn’t matter? The very idea is irrational. The idea is likewise contradicted by Christ’s own words in the parable of the sheep and the goats, where he makes it very clear that our eternal standing depends upon what we do in this life. The simple fact is that a Christian is not free to live as he wishes. He is a servant of Christ, and to be a servant by definition demands that he serve his master: that is to say, he must obey his master.
It’s not reasonable to say that we love Jesus on the one hand if we disobey him on the other. He has said that if we love him, we must keep his commands, so our obedience to him is the very measure of our love for him.
Unfortunately there are many Protestants who ignore this fact. They erroneously suppose that their obedience (or lack thereof) in this life has nothing to do with their eternal home. The Lord Jesus Christ unambiguously says otherwise. St. Paul says otherwise (Gal. 5:19-21). What we do in this life matters. Our obedience matters. Our sins matter. Thanks be to God that our sins may be forgiven, but we dare not presume upon God’s mercy.