Living a life of faith is its own reward. Nevertheless, the quoted text rewards us with eternal life and being raised up [from death] at the last day. Again, there is a concentrated gospel message in this text that goes a long way towards simplifying the sometimes frustrating experience of living the Christian life.
Now to the problems in spite of the wonderful statements outlined above. What happens when doubt or unbelief rear their ugly heads? How to proceed. If possible, it might be advisable to talk with a trusted parent, friend or minister who you know to be a strong and loving Christian. Even though belief is the core of your problem, persist in talking to God about your problem. Because he is a loving God and has your interest in mind, he will do what you ask of him if what you need is greater faith. If new Christians believe that they have little or imperfect faith keep in mind the words of the apostle::
"... God has distributed to each of you a measure of faith." Romans 12:3 [Paraphrased]God would hardly be a loving God if he asked us to believe in his Son for salvation and didn't meet us half way by giving us a quotient of start-up faith with which to move onto greater faith in the Christian experience.
There is still a lot more to this issue of faith, unbelief and renewal of faith, but the most important aspects, as I see them, have been outlined above. It is my sincere desire that at whatever stage you happen to be in the Christian walk, you may strengthen and find faith to meet your every need.