Build a friendship after an initial meeting

Invite them to spend time with you outside the normal context in which you usually see them.
For example, you could invite your church acquaintance out for bowling.

Keep in touch after your first meeting.
Check on them once in a while, but avoid calling them too much. They may get irritated by constant calls.

Show them that you care about them.
Listen to their problems and spend time with them. They will feel appreciated and valued.

Give them the freedom to be themselves.
Let them realize you have accepted them just the way they are.

Pay attention to their body language to understand them better.
Steer the conversation appropriately.