2 Cor 1:17-19 (NLT)
17 You may be asking why I changed my plan. Do you think I make my plans carelessly? Do you think I am like people of the world who say “Yes” when they really mean “No”? 18 As surely as God is faithful, my word to you does not waver between “Yes” and “No.” 19 For Jesus Christ, the Son of God, does not waver between “Yes” and “No.” He is the one whom Silas,a]">[a] Timothy, and I preached to you, and as God’s ultimate “Yes,” he always does what he says.
Today try to make a difference. If you mean yes, then say yes... but if you really mean no, then say so. There is nothing wrong with taking time for yourself or not wanting to do something for someone, but if you tell them yes when you really mean no, then you may be looked on as indecisive or as someone who can't be counted on. We should always be good to our word.