You can most certainly help others through your thoughts, and they can help you. Every good thought you send to another is a living force. However, the person you are sending the thought to has to be asking for the same thing you are sending. If the person does not want it, then they are not in harmony with your thought frequency, and it will not penetrate them.
You cannot create in another's life against their will, but if it is something they want, your thoughts are a real force that helps them.
May the joy be with you,