Breach of Promissory Note

Our church left a former building owner with an outstanding debt of $15,900. I signed a promissory note to pay $500.00 a month until the debt was dissolved. Over the next 11 months our church reduced the debt to $10,590.00. After not being able to pay $500.00 a month to finish a promissory note agreement I offered the owner $150.00 due to two families leaving our ministry after 20 years. They were tithing families. That left us with 6 adults and three children. I am a full-time pastor. Therefore, when tithing members leave I do not get my salary and it takes a tremendous nose dive and so does other church expenses. We could no longer pay the $500 a month. I offered to pay $150.00 a month and the owner became irate and decided to take me to court. He said that was to small of an amount it would take 6 years to pay it off. I received a summons today. However, he did accept and deposit the $150.00 we gave him last week. What can I do to avoid court?