The back legs of a frog are created as such for extreme jumping and this applies to some humans who are naturally gifted to be athletes etc. However, whatever our genetic make up is, in general we need to exercise to build up our muscles. Similarly, faith is a gift from God but we need to exercise our faith. Faith is trusting God in His love and faithfulness towards us, before we have even seen the tangible result yet in any given situation we need His help in. As we build up our faith daily, however small the occasion is, we will be more prepared for the occasions which require greater faith.
