Judges 9:19 If ye then have dealt truly and sincerely with Jerubbaal and with his house this day, then rejoice ye in Abimelech, and let him also rejoice in you:
Have you ever met someone and they stretch out their arm stiff in a manner which reminds you of someone who expects you to “kiss the ring”? They greet you with the phrase “I am delighted to meet you.”, and their posture says anything but delight.
Have you met someone and rather than shaking your hand they open up their arms and draw you in so close, it is almost like they are taking you into themselves. They say nothing.
Those are two extremes but in truth their actions are sincere. The words don’t matter, actions tell everything. Here in Judges 9:19 he points to actions rather than words by addressing “dealt truly” as the main focus and not words.
Then rejoice is added after actions are shown. The words follow the actions. So often we put the words out there and expect people to believe we are being sincere when we have done nothing to show our real intentions.
If the lost are to believe the gospel message we bring, sincerity must be established first so that the words will be received and believed. When Jesus sent out His disciples two by two and instructed them to enter into the homes of those who would receive them, He understood that sincerity opened the door.
1 John 3:18 My little children, let us not love in word, neither in tongue; but in deed and in truth.
To be sincere, you have to be sincere.