Combine cherries, sugar, water, and lemon juice in a medium saucepan. Bring to a gentle boil over medium heat, stirring occasionally. Reduce heat and simmer for about 15-20 minutes until cherries are soft and the syrup thickens slightly. Remove from heat and let cool completely. For a smoother texture, blend the mixture and strain through a fine sieve. Transfer to a clean jar or container and refrigerate. Use within a week for the best flavor.