Sometimes people think the Bible tells us that gain is godliness, but that's not what it says. Paul was talking about some leaders in the church and said, "...perverse disputings of men of corrupt minds... supposing that gain is godliness: from such withdraw thyself" (1 Timothy 6:4-5). These are people who think that if they are making it financially, then God must be involved.
But success is not proof that you are in God's will. You can succeed outside God's will. Jesus explained this when He spoke of two builders: "...whosoever heareth these sayings of mine, and doeth them, I will liken him unto a wise man, which built his house upon the rock... and it fell not... And every one that heareth... and doeth them not, shall be likened unto a foolish man, which built his house upon the sand..." (Matthew 7:24-27). These two builders succeeded in building.
Success alone is not proof that God is with you. Satan even tried to make Jesus 'successful' by offering Him all the kingdoms of the world. But Jesus later asked, "...what shall it profit a man, if he shall gain the whole world, and lose his own soul?" (Mark 8:36).
Some people say, "I thought they said this was not God's will, but I've done it and it worked". The real question is not whether it worked, but whether it pleased God. Jesus said, "...I do always those things that please him" (John 8:29). That should be your focus too.
When you go outside God's plan, things may still work. Even if you travel where God said not to, it doesn't mean you will die. If you marry the wrong person, it doesn't mean you will die. It means you have chosen a different path in destiny — a choice that favours you and not God.
God does not reward you for just doing many things. The Bible says, "If any man's work ABIDE... he shall receive a reward" (1 Corinthians 3:14). He rewards you for heartily doing His work, for fulfilling His purpose. This applies to ministry, finances, business, and relationships. Always seek the will of God, because you may succeed outside His will, but you may not be able to handle the troubles that come with it.
God does not place a warranty on products that are not His own. The challenges you face outside God's will are not covered by His grace, but challenges you face following His plan are fully accounted for. David faced challenges, Joseph faced challenges, but God turned them into testimonies because they were in His plan. Any trouble you face following God's plan is on God's account, and He has already paid for it. But when you face trouble outside His will, you face it alone.
Be committed to fulfilling God's plan for your life. Don't follow trends. Don't follow what others are doing. Choose God's will above all else. The Bible says, "...be not conformed to this world: but be ye transformed by the renewing of your mind..." (Romans 12:2). Only those who truly love God are patient enough to follow His plan.