In God's economy, it is either hot or cold. You are either saved or lost. You are either under grace or under law. You are either under the old covenant or the new covenant. He don't deal with us in a lukewarm middle-ground where nothing is consistent. And I think it makes sense. He kind of made it clear in the message to the church in Laodicea - 'I know your deeds, that you are neither cold nor hot. I wish you were either one or the other! So, because you are lukewarm—neither hot nor cold—I am about to spit you out of my mouth.
The mixture is not good. Paul was irritated by galatianism, the mixture of law and grace, that he even called them 'foolish'. It's better that we are either be under the law or under the grace. Those who are trying fervently to live a righteous life under law will possibly realize their futility and come to the knowledge of grace one day. There is hope for them. But there is only a very little hope for those who mix it. They think they are under grace, but in reality they are not.
When we fall from grace, we are naturally falling into law. But to get to the mixture, there has to have a deliberate effort. Through the illustration of the New wine in the old wineskin , Jesus showed us this. If we pour the new wine into the old wineskin, the new wine will break the old hard wineskin as it continues to ferment and run out. Both, the wine and the wineskin are ruined and lost. Who want to tear a patch from a new garment and sew it on an old one? It will make both garments useless and ruined.
Do you want to hold onto the law? Hold on to it tight! Put your best of the best efforts to live it out. (And when you are tired trying to measure up, let me know, I will tell you about a GIFT). But don't try to sprinkle little bit of grace here and there. It will spoil both God's holy law and His awesome grace.
Again, please don't see this as a doctrinal hair splitting. The above mentioned error of mixture has produced enough organizational, institutional, business-like enterprises called 'churches', which are evidently hindering people from having a relationship with a loving God, who has exhibited His unconditional, and unfailing act of love and Grace upon the cross.
God is the same yesterday, today and forever, so how can you say that He has changed after Jesus's appearance?
Well, He HASN'T changed, but THINGS have changed!
My wife and I got married on December 28, 2002. One day before, which is December 27th, we couldn't express our intimacy beyond certain limits. But in 24 hours, we entered into a new relationship which gave us freedom for intimacy in a new level. Have I changed in 24 hours? NO! But THINGS have changed!
What if we still live in an unmarried mentality?
That's precisely what some Christians do today, they live in an unmarried mentality. They are not realizing the death and resurrection of Christ has changed THINGS. The same God who showed His presence in the holy of holies of an earthly tabernacle where only high priests were allowed to enter once in an year, torn that curtain down from the top to bottom, stepped out of His glory, came to us as a baby born in a manger, lived among us as a mere carpenter, died for us and trampled all the hindrances which kept us away from having an intimate relationship with Him, gloriously resurrected on the 3rd day and imparted His LIFE to us and placed us in Him and declared that we are His bride and nothing can separate us from His love; He lives IN Us today.
THINGS have really changed and now it's upto us to live in this new level of intimacy, love and togetherness instead of going back to the unmarried attitude.