The time to act is as soon as you have reasoned as much as needed to be convinced. If you know what you need to do, it is time to act.
If you delay action, the belief will fade, the desire will fade, and even the reasons will fade. Delaying doesn’t change the facts, but it will change your belief. Light cleaves to light. If you resist or delay acting to conform yourself to your beliefs, you will lose light. Your belief will diminish.
Get moving now—no matter how small the first step. If you do small things now , you will do great things later . If you don’t do small things now, you won’t do even the small things later.
But how do you know when your reasons are sufficient to act?
One dimension of faith is the degree of action in response to the degree of signal. How well do you have to understand the outcome before acting? Do you act once the outcome is obviously beneficial, or do you wait until you have a perfect knowledge of it? Remember, a perfect knowledge is not faith, and requiring that degree of detail will preclude many desirable outcomes which can’t be had by playing it safe. Something can be rationally justified even if the reasons are small or faint, and this can be the case even when the implications are enormous: “by small means the Lord can bring about great things.” (1 Nephi 16:29)
If you follow the faith process, the Lord will always show you what is right (see 1 Nephi 15:11 and Moroni 10:5). However, God is only required to show you a sufficient reason. He makes no promise to show you the full implications of the decision, or to present the evidence in as compelling a light as the implications merit. In fact, we are told the opposite: “by small and simple things are great things brought to pass; and small means in many instances doth confound the wise.” (Alma 37:6) The greater the action in response to lesser signal, the greater the outcomes possible.
One example of this is the outcome that resulted from the mission of Ammon and his brothers, who made the decision to go based on far smaller expectations of outcome:
1 And now, these are the words of Ammon to his brethren, which say thus: My brothers and my brethren, behold I say unto you, how great reason have we to rejoice; for could we have supposed when we started from the land of Zarahemla that God would have granted unto us such great blessings?
2 And now, I ask, what great blessings has he bestowed upon us? Can ye tell?
3 Behold, I answer for you; for our brethren, the Lamanites, were in darkness, yea, even in the darkest abyss, but behold, how many of them are brought to behold the marvelous light of God! And this is the blessing which hath been bestowed upon us, that we have been made instruments in the hands of God to bring about this great work.
4 Behold, thousands of them do rejoice, and have been brought into the fold of God.
5 Behold, the field was ripe, and blessed are ye, for ye did thrust in the sickle, and did reap with your might, yea, all the day long did ye labor; and behold the number of your sheaves! And they shall be gathered into the garners, that they are not wasted.
6 Yea, they shall not be beaten down by the storm at the last day; yea, neither shall they be harrowed up by the whirlwinds; but when the storm cometh they shall be gathered together in their place, that the storm cannot penetrate to them; yea, neither shall they be driven with fierce winds whithersoever the enemy listeth to carry them.
7 But behold, they are in the hands of the Lord of the harvest, and they are his; and he will raise them up at the last day.
8 Blessed be the name of our God; let us sing to his praise, yea, let us give thanks to his holy name, for he doth work righteousness forever.
9 For if we had not come up out of the land of Zarahemla, these our dearly beloved brethren, who have so dearly beloved us, would still have been racked with hatred against us, yea, and they would also have been strangers to God. (Alma 26)
It is of utmost importance, therefore, to pay attention to the information you have access to, and interpret it honestly! Whether through the intervention of others or your own experience, you aren’t likely to listen when presented with signals that contradict the outcome or paths you desire.
Humans don’t want to hear the truth. They don’t want to hear the way to obtain something better. They want to hear that what they are already doing is good enough, that what they have is all there is to have, and that the evidence that these things are not true is a figment of their imagination.
It takes faith to believe that what God has is superior. It takes faith to notice the information he gives you, and to trust in reason rather than what you wish were true.
Do the best you know, and pay attention to adapt to any new information as it comes.