One of the ObeyGC2 values is that one should listen and learn before acting.
This is not only a principle in good missiology, but a good principle for life in general as well. First, we will be better received if we do this. We should always go as learners before training others. This is definitely not an issue of becoming a subject matter expert on something. Training is all about taking someone from where they are to where you want them to be in knowledge, attitude and ability. Being a subject matter expert in some field only enables you to know where you want to get someone to. It does not equip you to know where you are taking them from. That requires learning from them. It requires relationship. Your training or serving cannot be appropriate without this process.
James 1:19
19 My dear brothers, take note of this: Everyone should be quick to listen, slow to speak and slow to become angry,
1 Thess 2:6b-8
As apostles of Christ we could have been a burden to you, 7 but we were gentle among you, like a mother caring for her little children. 8 We loved you so much that we were delighted to share with you not only the gospel of God but our lives as well, because you had become so dear to us.