From “Growing in the character of a disciple”: Chapter 7 – Some more of the ways in which we must become faithful
The Bible is full of principles that guide us in how to approach decisions and situations. Life is so varied that infinite permutations of circumstances can arise. We then have to decide which principles to apply, or which principle comes first on a particular occasion. At such times, we need to be guided by conscience. That is the gift God gives each of us to guide us. It’s like using a compass in a heavy storm, when we can’t get directions from anything else.
We can ask God and He will guide us through our conscience. We will just know that a certain course of action doesn’t feel right, even if we can’t explain why, and even though it seems there are many good points in favour of it. When that happens, always follow your conscience and never go against it.
Be very careful before you make any vow. God will hold you to your word.
Be careful with your words. Don’t make rash promises to God, or anybody else, without proper consideration and reflection. He will hold you to what you say. Therefore avoid making any promise or vow unless you have thought it through and fully intend to honour it. Even then, don’t make vows at all, unless you are really sure God wants you to do so:
4When you make a vow to God, do not be late in paying it; for He takes no delight in fools Pay what you vow! 5It is better that you should not vow than that you should vow and not pay. 6Do not let your speech cause you to sin and do not say in the presence of the messenger of God that it was a mistake. Why should God be angry on account of your voice and destroy the work of your hands?Ecclesiastes 5:4-6 (NASB)