Nothing is impossible for God - not even to bring us into His perfect will, after we have failed miserably and repeatedly. Only our unbelief can hinder Him. If you say, "But I have messed up things so many times. It is impossible for God now to bring me into His perfect plan", then it will be impossible for God, because YOU cannot believe in what He can do for you. But Jesus said that nothing is impossible for God to do for us - if only we believe. "Let it be done to you according to your faith", is God's law in all matters (Matt. 9:29). We will get what we have faith for. If we believe that something is impossible for God to do for us, then it will not be fulfilled in our lives. On the other hand you will discover at the judgment seat of Christ that another believer who had made a greater mess of his life than you, nevertheless fulfilled God's perfect plan for his life - just because he believed that God could pick up the broken pieces of his life and make something "very good" out of it. What regret there will be in your life in that day, when you discover that it was not your failures (however many they may have been) that frustrated God's plan in your life, but your unbelief!
"The reason the Son of God was manifested was to undo (dissolve) the works the devil has done (1 Jn. 3:8 Amplified Bible). That verse actually means that Jesus came" to untie all the knots that the devil has tied" in our lives. Picture it like this: When we were born, we could say that God gave each of us a perfectly rolled ball of string. As we began living each day, we began to unroll that ball of string and we began tying knots into it(sinning). Today after many years of unrolling the string, we despair, as we see the thousands of knots that we see in it. But Jesus has come to "untie the knots the devil has tied". So there is hope even for those with the most knotted strings. The Lord can untie every knot and give you a perfect ball of string in your hands once again. This is the message of the gospel: You can make a new beginning. You say, "That is impossible!". Well then, it will be done to you according to your faith. It will be impossible in your case. But I hear some one else whose life is worse than yours, saying, "Yes, I believe that God will do that in me". To him too it will be according to his faith. In his life, God's perfect plan will be fulfilled.
In Jeremiah 18:1-6, God spoke His word to Jeremiah through a practical illustration. Jeremiah was asked to go to a potter's house, and there he saw the potter trying to make a vessel. But the vessel "was spoiled in the hand of the potter". So what did the potter do? "He remade it into another vessel, as it pleased the potter to make". Then came the application: "Can I not, O ............... deal with you as this potter does?", was the Lord's question (v. 6). (Fill in your name in those dotted lines, and that would be God's question to you). If there is a godly sorrow in your life for all your failures, then even if your sins are like scarlet or red like crimson, not only will your heart be made as white as snow - as promised under the old covenant (Isa. 1:18) - but God promises even more under the new covenant: "I will not remember your sins any more" (Heb. 8:12).
Whatever your blunders or failures, you can make a new beginning with God. And even if you have made a thousand new beginnings in the past and have come to failure, you can still make the 1001st new beginning today. God can still make something glorious out of your life. While there is life, there is hope. So, never fail to trust God. He cannot do many mighty works for many of His children, not because they have failed Him in the past, but because they will not trust Him now. Let us then "give glory to God by being strong in faith" (Rom. 4:20), trusting Him in the days to come for the things which we considered impossible up until now. You can have hope, no matter how much you may have failed in the past, if only you will acknowledge your failures, be humble and trust God.