Ultimately, the way God cleans us is by the blood of Jesus. Jesus died and rose again, paying the debt of our sin and this is how we are made clean in God's sight. If we take our sins to God, repent and ask for forgiveness, it is given to us freely because of Jesus. These sins are no longer there to mark us or be counted against us because Jesus has washed them away and we are clean....even cleaner than we managed to get the classroom walls, I might add!
Having said this, once we are saved and washed by Jesus, there is still a sort of ongoing cleaning process until we get to Heaven.
"And I am sure that God, who began the good work within you, will continue his work until it is finally finished on that day when Christ Jesus comes back again." - Philippeans 1:6
I believe God can use a variety of cleaning methods on us. Probably whatever is most appropriate for the job! It might be that it requires us to take some form of action, for example, it may be that we are holding tightly onto a sticky lump of hurt where we have not forgiven someone. Here, God may bring this to our concious attention and shows us that we must repent of this unforgiveness, let go of the hurt and forgive those that have wronged us so that we can be made clean and free. Other times He cleans us in ways we can't see, with the gentle touch of His Holy Spirit. This kind of cleaning often seems to happen when we are truly worshipping Him or are crying out to Him in prayer and we feel Him close. We are not always aware of what He is doing, but His Holy Spirit moves in us and brings deep healing. Often in these times people find themselves crying without explanation. It could be that the work He was doing is revealed to us at a later time.
When we become aware of any dirt in our lives, hidden or unhidden, it is definitely better to bring it to God for cleaning than to ignore it or to try and cover over it. It can be that way when it comes to apologising to someone that we have wronged. Am I the only one that has ever thought "I shouldn't have done that...I'll just lie low until it settles down and they forget about it." rather than coming forward and dealing with the problem? When we apologise to people not only can it quicken the healing process for the person that we have hurt, it also brings a freedom to us. If we do not deal with sin in our lives, if we do not admit that is was wrong, we are welcoming sin into our lives. We are leaving it to grow and fester in us which will cause bigger problems further down the line. It makes the way for habit and over time it can warp our sense of right and wrong. By choosing not to admit that something we have done is wrong, we stifle our conscience and the next time we repeat this sin, we feel less guilty. Things might look OK on the surface, but underneath there are bad roots growing. We know that where roots grow below the ground, they eventually appear above the surface, they don't stay hidden for long! This is why we should deal with the dirt of sin as soon as we can.
"Therefore, since we are surrounded by such a huge crowd of witnesses to the life of faith, let us strip off every weight that slows us down, especially the sin that so easily hinders our progress. And let us run with endurance the race that God has set before us. We do this by keeping our eyes on Jesus, on whom our faith depends from start to finish. He was willing to die a shameful death on the cross because of the joy he knew would be his afterward. Now he is seated in the place of highest honour beside God's throne in heaven." - Hebrews 12:1-2
The base coat for the mural, would not be dissimilar to a foundation layer.
"Anyone who listens to my teaching and obeys me is wise, like a person who builds a house on solid rock. Though the rain comes in torrents and flood waters rise and the winds beat against the house, it won't collapse, because it is built on rock. But anyone who hears my teaching and ignores it is foolish, like a person who builds a house on sand. When the rains and floods come and the winds beat against the house, it will fall with a mighty crash." - Matthew 7:24-27
Here we read about the importance of a solid foundation. For painting (especially with oils like I use back in the studio), the foundation layer on which you paint is key. Some materials dry by a form of combustion and so you have to be careful that you are painting on a suitable surface, otherwise the paints could eventually burn through the surface and have your work disintegrate. If you paint on a piece of wood that has not been reinforced with a frame or support at the back, the wood will eventually warp and your work will be ruined and fit only for the bin. By not building on a solid foundation, or taking the right measures as you start a painting, it can result in a waste of time and materials...as well as some embarrassment!
When Jesus talks about building on a solid foundation, he means he is the foundation on which we should build our lives. On this earth, we can live without him. We can live to please ourselves, finding good jobs, earning money, buying nice things and making our earthly houses look beautiful. But when we reach the end of life and we stand before God, will all those piles of money or our earthly success stay with us? No. They will disappear like a house made of sand, not something that lasts. It would become apparent what a waste of time and effort chasing after these things was. And I imagine we'd feel quite embarrassed with nothing worth while to show for our many years of life!
"Don't store up your treasures here on earth, where they can be eaten by moths and get rusty, and where thieves break in and steal. Store your treasures in heaven, where they will never become moth-eaten or rusty and where they will be safe from thieves. Wherever your treasure is, there your heart and thoughts will be." - Matthew 6:19-21
If we build our lives on Jesus, following his lead and being obedient to his word, he can use our lives to build good things that will last! Things built in faith, love and hope that will endure. (see 1 Corinthians 13:13)
Without the grid we would have still managed to make a mural and it probably would have looked nice but it wouldn't necessarily be very accurate! We probably would have made countries bigger or smaller than we should have, or we might have put them too far apart or out of line. This reminded me of how we must continually use God's word as a guide for life and if we do this we won't go far wrong! Without using God's word as a guide it's easy for our focus to stray and for different areas of life to take priority and be blown out of proportion. When we lift our gaze from Jesus and start trying to tackle problems on our own we can end up in a right mess. An example of this could be that instead of trusting God that we don't have to worry about anything and He will meet our needs if we seek His Kingdom first (Matthew 6:31-33), we make our needs our primary concern. We give room to panic and worry (that shouldn't even be on our map!) and we give areas like finance and earthly security too much room, making them bigger than they should be. It doesn't take long before we then start measuring other areas of life against these already warped parts and before you know it the whole picture is completely out of line and proportion. When you realise this, it takes a lot of whittling and readjusting to get it back to how it should be. This is why we should continually immerse ourselves in the word of God - it keeps us on track, it keeps our focus on the right things and it keeps everything in proportion!