You said there are different ways of approaching God: action, devotion and knowledge. If one person possesses all these qualities, will it help his progress?
Certainly it helps. The attitude of service, the attitude of devotion and the quest for knowledge, taken all together, will help us make a balanced progress. But at some point in our life we will have to find the one that inspires us most and give it most importance. Each soul has its own way of moving. Here on earth, we are inspired to progress according to our soul's propensity. If we accept all these paths, it is a great help; at the same time, we have to pay most attention to our own soul's way, the way that gives us the greatest fulfilment according to our deepest aspiration.