Saint Augustine once said that you can tell what a man loves by what does in his everyday actions. A man who lives a superficial life that revolves around meaningless temporal trivialities is a man who loves the world, not God. Many people claim to believe in God, but their lives reflect something different. Can a person "believe" in God when they do not pray, or when they do not attempt to live their lives according to God's commands? Saint Augustine also said, “If you believe what you like in the gospels, and reject what you don’t like, it is not the gospel you believe, but yourself.” A litmus test can be given according to how we live our lives day in and day out as to whether we can truly call ourselves "believers". The list below is a good starting point to determine if you truly believe in God, or whether you are just paying lip service. (Matthew 15:18)
1. Do you actually pray everyday? If you are not spending time in prayer with God, then you do not truly love Him. The old saying that those who do not pray have no chance of spending eternity with God, those who spend little time in prayer have little chance and those who spend much time in prayer have a great chance is true. Our Lord said that many would try to enter by the narrow gate, but many would fail. (Matthew 7:13-14) Prayer is the first litmus test as to whether one truly believes in God. If we read the Scriptures it is clear that prayer is a manifestation of the love of God. "Pray without ceasing. In all circumstances give thanks, for this is the will of God for you in Christ Jesus" (1 Thes 5:17-18) Saint Alphonsus Liguori tells us according to the Fathers of the Church, "Hence it is that the generality of theologians, following St. Basil, St. Chrysostom, Clement of Alexandria, St. Augustine, and other Fathers, teach that prayer is necessary to adults, not only because of the obligation of the precept (as they say), but because it is necessary as a means of salvation. That is to say, in the ordinary course of Providence, it is impossible that a Christian should be saved without recommending himself to God, and asking for the graces necessary to salvation. St. Thomas teaches the same: 'After baptism, continual prayer is necessary to man, in order that he may enter heaven; for though by baptism our sins are remitted, there still remain concupiscence to assail us from within, and the world and the devil to assail us from without.' The reason then which makes us certain of the necessity of prayer is shortly this, in order to be saved we must contend and conquer: He that strives for the mystery is not crowned except he strive lawfully (2 Tim. 2,5). But without the divine assistance we cannot resist the might of so many and so powerful' enemies: now this assistance is only granted to prayer; therefore without prayer there is no salvation."
2. Do you attempt to live by God's commandments? Jesus said that if you love Him you will keep His commandments. (John 14:15) This also means that the opposite is true. If you live your life contradicting His commandments then you do not love Him. A person who truly believes in God takes His commandments seriously. He tries to live according to the teachings that Our Lord gave him. This means one must conform themselves to Christ. In todays Protestant influenced culture many hold the false notion that Jesus pays for our sins and then we have no further obligation to actually live the commandments He gave to us. Many foolishly think that since Christ died for them, that He no longer holds them accountable for their actions. Yet if we read Scripture it is clear that those who live sinful lives do not inherit the kingdom of heaven. (1 Corinthians 6:8-10) Christ has given us the means to actually keep His commandments through grace. One must not only believe in their minds that Christ died for them, but they must also act upon what Christ tells them in virtue of His passion. A person must actually live by faith filled works which God grants through grace. This truth is heavily emphasized in Scripture. Sadly many willfully ignore this reality and live as if Christ has stamped their ticket and there is nothing more to worry about. I would encourage those who shallowly think this way to meditate on the following Scripture passages. (James 2:17, 26, Matthew 7:21, Ephesians 2:10) Living by the commandments means living by all ten of them. I cannot cover this topic in depth here in this post. I will further elaborate on only one which should orient a person towards the other nine.
3. Do you do what He tells you to do and do you give Him the honor and worship that is due to Him? Our Blessed Mother at the Wedding at Cana told those around her to do as Jesus commanded them to do. This is a universal teaching given to all those claiming to love Christ. Christ established one Church which He built upon Saint Peter. (Matthew 16:18) Jesus gave Peter and the apostles in communion with Him, the authority to continue to teach His Word. They have the authority to bind and loose. (Matthew 16:19) Those who listen to Christ are those who faithfully attend Mass on Sundays and Holy days of obligation. They are the ones who confess their sins after after offending God and turn away from sin. They receive the Sacraments faithfully and honor God because there is a worship that is due to Him alone. In effect they do what God commands them to do because they love Him. Those who sit at home watching the ballgame every Sunday clearly love the ballgame more than they love God. This is in a nutshell what the first commandment teaches. It teaches that one will put nothing above God and that one will worship God because God deserves it, and also because he loves God. Those who consciously do not go to Mass and give the honor and worship that is due to God, do not truly love Him.
Although there is much more that can be said on this subject, this gives a very basic outline on what belief in God actually requires of us. Belief in God is not a Pollyanish 'pie in the sky' idea that there is some vague higher power who saves everyone who holds to some mental idea of a "god." Unfortunately this is the "faith" of many people today. It is a superficial belief in God that causes the loss of so many souls. Let us all remain in prayer and in obedience to God or we shall lose our souls.